diff --git a/src/osgPlugins/txp/TXPNode.cpp b/src/osgPlugins/txp/TXPNode.cpp
index b6161bf9f..d6f0fb2d2 100644
--- a/src/osgPlugins/txp/TXPNode.cpp
+++ b/src/osgPlugins/txp/TXPNode.cpp
@@ -134,8 +134,6 @@ void TXPNode::traverse(osg::NodeVisitor& nv)
 
             //std::cout<<"   found " << tileMapper._tileMap.size() << std::endl;
             
-            tileMapper->checkValidityOfAllVisibleTiles();
-            
             cv->setUserData(tileMapper.get());
 
 #ifdef PRINT_TILEMAPP_TIMEINFO        
diff --git a/src/osgPlugins/txp/TileMapper.cpp b/src/osgPlugins/txp/TileMapper.cpp
index 16d16dd85..c2569266e 100644
--- a/src/osgPlugins/txp/TileMapper.cpp
+++ b/src/osgPlugins/txp/TileMapper.cpp
@@ -11,8 +11,11 @@
  * OpenSceneGraph Public License for more details.
 */
 
+/*	Dec 2010 - TileMapper was fixed and simplified
+	Nick
+*/
+
 #include "TileMapper.h"
-//#include "TXPTileNode.h"
 #include "TXPPagedLOD.h"
 
 #include <osg/Material>
@@ -22,20 +25,18 @@ using namespace txp;
 float TileMapper::getDistanceToEyePoint(const osg::Vec3& pos, bool withLODScale) const
 {
     if (withLODScale)
-	return (pos-getEyeLocal()).length()*getLODScale();
+        return (pos-getEyeLocal()).length()*getLODScale();
     else
-	return (pos-getEyeLocal()).length();
+        return (pos-getEyeLocal()).length();
 }
 
 inline TileMapper::value_type distance(const osg::Vec3& coord,const osg::Matrix& matrix)
 {
 
-    //std::cout << "distance("<<coord<<", "<<matrix<<")"<<std::endl;
-
     return -((TileMapper::value_type)coord[0]*(TileMapper::value_type)matrix(0,2)+
-	     (TileMapper::value_type)coord[1]*(TileMapper::value_type)matrix(1,2)+
-	     (TileMapper::value_type)coord[2]*(TileMapper::value_type)matrix(2,2)+
-	     matrix(3,2));
+             (TileMapper::value_type)coord[1]*(TileMapper::value_type)matrix(1,2)+
+             (TileMapper::value_type)coord[2]*(TileMapper::value_type)matrix(2,2)+
+             matrix(3,2));
 }
 
 float TileMapper::getDistanceFromEyePoint(const osg::Vec3& pos, bool withLODScale) const
@@ -44,9 +45,9 @@ float TileMapper::getDistanceFromEyePoint(const osg::Vec3& pos, bool withLODScal
     float dist = distance(pos,matrix);
     
     if (withLODScale)
-	return dist*getLODScale();
+        return dist*getLODScale();
     else
-	return dist;
+        return dist;
 }
 
 void TileMapper::apply(osg::Node& node)
@@ -58,7 +59,7 @@ void TileMapper::apply(osg::Node& node)
     }
 
     if (isCulled(node))
-	return;
+        return;
 
     // push the culling mode.
     pushCurrentMask();
@@ -78,7 +79,7 @@ void TileMapper::apply(osg::Group& node)
     }
 
     if (isCulled(node))
-	return;
+        return;
 
     // push the culling mode.
     pushCurrentMask();
@@ -87,8 +88,6 @@ void TileMapper::apply(osg::Group& node)
     
     if (tid)
     {
-        _tileStack.push_back(TileStack::value_type(*tid,&node));
-
         _containsGeode = false;
     }
 
@@ -102,44 +101,8 @@ void TileMapper::apply(osg::Group& node)
 
             _containsGeode = false;
 
-#if 0
-            std::cout<<"found Group="<<tid->lod
-                     <<"  X="<<tid->x
-                     <<"  Y="<<tid->y
-                     <<"  ptr="<<&node<<std::endl;
-
-            std::cout<<"      inheritance list "<<_tileStack.size()<<std::endl;
-            for(TileStack::iterator itr=_tileStack.begin();
-                itr!=_tileStack.end();
-                ++itr)
-            {
-                std::cout<<"      LOD="<<itr->first.lod
-                         <<" X="<<itr->first.x
-                         <<" Y="<<itr->first.y
-                         <<" className="<<itr->second->className()
-                         <<" ptr="<<itr->second<<std::endl;      
-            }
-
-            
-            osg::StateSet* stateset = node.getOrCreateStateSet();
-            osg::Material* material = new osg::Material;
-            material->setColorMode(osg::Material::OFF);
-            stateset->setAttribute(material);
-            
-            switch(tid->lod)
-            {
-            case(0): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,1.0f,1.0f,1.0f)); break;
-            case(1): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,0.0f,0.0f,1.0f)); break;
-            case(2): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,1.0f,0.0f,1.0f)); break;
-            case(3): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,0.0f,1.0f,1.0f)); break;
-            case(4): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,0.0f,1.0f,1.0f)); break;
-            }
-            
-#endif            
-
         }
     
-        _tileStack.pop_back();
     }
 
     // pop the culling mode.
@@ -154,7 +117,7 @@ void TileMapper::apply(osg::Geode&)
 void TileMapper::apply(osg::PagedLOD& node)
 {
     if (isCulled(node))
-	return;
+        return;
 
     // push the culling mode.
     pushCurrentMask();
@@ -162,11 +125,7 @@ void TileMapper::apply(osg::PagedLOD& node)
     TXPPagedLOD* txpPagedLOD = dynamic_cast<TXPPagedLOD*>(&node);
     if (txpPagedLOD)
     {
-                                   
-        _tileStack.push_back(TileStack::value_type(txpPagedLOD->_tileIdentifier,&node));
-
         _containsGeode = false;
-
     }
 
     traverse(node);
@@ -178,41 +137,7 @@ void TileMapper::apply(osg::PagedLOD& node)
             insertTile(txpPagedLOD->_tileIdentifier);
 
             _containsGeode = false;
-
-#if 0
-            std::cout<<"found txpPagedLOD LOD="<<txpPagedLOD->_tileIdentifier.lod
-                     <<"  X="<<txpPagedLOD->_tileIdentifier.x
-                     <<"  Y="<<txpPagedLOD->_tileIdentifier.y
-                     <<"  ptr="<<txpPagedLOD<<std::endl;
-
-            std::cout<<"      inheritance list "<<_tileStack.size()<<std::endl;
-            for(TileStack::iterator itr=_tileStack.begin();
-                itr!=_tileStack.end();
-                ++itr)
-            {
-                std::cout<<"      LOD="<<itr->first.lod
-                         <<" X="<<itr->first.x
-                         <<" Y="<<itr->first.y
-                         <<" className="<<itr->second->className()
-                         <<" ptr="<<itr->second<<std::endl;      
-            }
-
-            osg::StateSet* stateset = txpPagedLOD->getOrCreateStateSet();
-            osg::Material* material = new osg::Material;
-            material->setColorMode(osg::Material::OFF);
-            stateset->setAttribute(material);
-
-            switch(txpPagedLOD->_tileIdentifier.lod)
-            {
-            case(0): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,1.0f,1.0f,1.0f)); break;
-            case(1): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,0.0f,0.0f,1.0f)); break;
-            case(2): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,1.0f,0.0f,1.0f)); break;
-            case(3): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(0.0f,0.0f,1.0f,1.0f)); break;
-            case(4): material->setEmission(osg::Material::FRONT_AND_BACK,osg::Vec4(1.0f,0.0f,1.0f,1.0f)); break;
-            }
-#endif            
         }
-        _tileStack.pop_back();
     }
 
     // pop the culling mode.
@@ -221,212 +146,10 @@ void TileMapper::apply(osg::PagedLOD& node)
 
 void TileMapper::insertTile(const TileIdentifier& tid)
 {
-    _tileMap.insert(TileMap::value_type(tid,_tileStack));
+    _tileMap.insert(TileMap::value_type(tid,1));
 }
 
-bool TileMapper::canParentBeTraversed(const TileIdentifier& tid) const
-{
-    // find the tiles parents.
-    TileMap::const_iterator itr = _tileMap.find(tid);
-    if (itr==_tileMap.end())
-    {
-#if 0
-        // not found tile in _tileMap, what should we do??
-        // return true as a fallback right now.
-        std::cout<<"TileMapper::canDescend() Not found tile in map"<<std::endl;
-#endif
-        return true;
-    }
 
-    const TileStack& ts = itr->second;
-    
-    // note tile here, is tid's parent.
-    const TileStack::value_type* tile = (ts.size()>=2) ? &ts[ts.size()-2] : 0;
-
-    if (!tile)
-    {
-        // no self!!! so we can descend safely?!! shouldn't ever get here.
-        //std::cout<<"TileMapper::canDescend() tile==0"<<std::endl;
-        return true;
-    }
-
-
-    // note parent here, is tid's parents parent.
-    const TileStack::value_type* parent = (ts.size()>=3) ? &ts[ts.size()-3] : 0;
-    
-    
-
-    if (!parent)
-    {
-        // no parent so we can descend safely.
-        return true;
-    }
-    
-    bool tileHasNorthNeighour = _tileMap.count(TileIdentifier(tid.x,tid.y+1,tid.lod))!=0;
-    bool tileHasEastNeighour = _tileMap.count(TileIdentifier(tid.x+1,tid.y,tid.lod))!=0;
-    bool tileHasSouthNeighour = _tileMap.count(TileIdentifier(tid.x,tid.y-1,tid.lod))!=0;
-    bool tileHasWestNeighour = _tileMap.count(TileIdentifier(tid.x-1,tid.y,tid.lod))!=0;
-    
-    if (tileHasNorthNeighour && tileHasEastNeighour && tileHasSouthNeighour && tileHasWestNeighour)
-    {
-        // tile has neigbours on all sides at the same lod level, so its safe to descend.
-        //std::cout<<"TileMapper::canDescend() has neightbours on all sides"<<std::endl;
-        return true;
-    }
-
-    // FIXME: this guy gives us wrong parent
-    // Nick 2010/12/12
-#if 0
-    const TileIdentifier& parent_tid = parent->first;
-#else
-    TileIdentifier parent_tid(tid.x/2,tid.y/2,tid.lod-1);
-#endif
-    
-    bool parentHasNorthNeighour = _tileMap.count(TileIdentifier(parent_tid.x,parent_tid.y+1,parent_tid.lod))!=0;
-    bool parentHasEastNeighour = _tileMap.count(TileIdentifier(parent_tid.x+1,parent_tid.y,parent_tid.lod))!=0;
-    bool parentHasSouthNeighour = _tileMap.count(TileIdentifier(parent_tid.x,parent_tid.y-1,parent_tid.lod))!=0;
-    bool parentHasWestNeighour = _tileMap.count(TileIdentifier(parent_tid.x-1,parent_tid.y,parent_tid.lod))!=0;
-    
-    // FIXME: this guy gives us wrong parent
-    // Nick 2010/12/12
-#if 0
-    // identify whether the tile is a NE/SE/SW/NW tile relative to its parent.
-    osg::Vec3 delta = tile->second->getBound().center() - parent->second->getBound().center();
-    
-    if (delta.y()>=0.0f) // noth side
-    {        
-        if (delta.x()>=0.0f)
-        {
-            // NE, only traverse if our parent doesn't have any neighbours to the north or east.
-            return (!parentHasNorthNeighour && !parentHasEastNeighour);
-        }
-        else 
-        {
-            // NW, only traverse if our parent doesn't have any neighbours to the north or west.
-            return (!parentHasNorthNeighour && !parentHasWestNeighour);
-        }
-    }
-    else // south side
-    {
-        if (delta.x()>=0.0f)
-        {
-            // SE, only traverse if our parent doesn't have any neighbours to the south or east.
-            return (!parentHasSouthNeighour && !parentHasEastNeighour);
-        }
-        else 
-        {
-            // SW, only traverse if our parent doesn't have any neighbours to the south or west.
-            return (!parentHasSouthNeighour && !parentHasWestNeighour);
-        }
-    }
-#else
-    // identify whether the tile is a NE/SE/SW/NW tile relative to its parent.
-    osg::Vec3 delta(tid.x%2,tid.y%2,0);
-
-    if (delta.y()>0.0f) // noth side
-    {
-        if (delta.x()>0.0f)
-        {
-            // NE, only traverse if our parent doesn't have any neighbours to the north or east.
-            return (!parentHasNorthNeighour && !parentHasEastNeighour);
-        }
-        else 
-        {
-            // NW, only traverse if our parent doesn't have any neighbours to the north or west.
-            return (!parentHasNorthNeighour && !parentHasWestNeighour);
-        }
-    }
-    else // south side
-    {
-        if (delta.x()>0.0f)
-        {
-            // SE, only traverse if our parent doesn't have any neighbours to the south or east.
-            return (!parentHasSouthNeighour && !parentHasEastNeighour);
-        }
-        else 
-        {
-            // SW, only traverse if our parent doesn't have any neighbours to the south or west.
-            return (!parentHasSouthNeighour && !parentHasWestNeighour);
-        }
-    }
-#endif
-}
-
-void TileMapper::checkValidityOfAllVisibleTiles()
-{
-    typedef std::vector<TileIdentifier> ToRemoveList;
-    typedef std::vector<TileStack> ToAddList;
-
-    ToRemoveList toRemoveList;
-    ToAddList toAddList;
-
-    do
-    {
-//        std::cout<<"doing checkAllVisibleTiles() loop with "<<_tileMap.size()<<std::endl;
-
-        toRemoveList.clear();
-        toAddList.clear();
-
-        for(TileMap::iterator itr=_tileMap.begin();
-            itr!=_tileMap.end();
-            ++itr)
-        {
-            if (!canParentBeTraversed(itr->first))
-            {
-                // need to remove.
-                toRemoveList.push_back(itr->first);
-
-                // trim the end of itr's TileStack and add into toAddList
-                toAddList.push_back(itr->second);
-
-//                 std::cout<<"Tile failed"
-//                          <<" LOD="<<itr->first.lod
-//                          <<" X="<<itr->first.x
-//                          <<" Y="<<itr->first.y<<std::endl;
-
-            }
-        }
-
-        for(ToRemoveList::iterator ritr=toRemoveList.begin();
-            ritr!=toRemoveList.end();
-            ++ritr)
-        {
-            //std::cout<<"Removing Tile"<<std::endl;
-            _tileMap.erase(*ritr);
-        }
-
-        for(ToAddList::iterator aitr=toAddList.begin();
-            aitr!=toAddList.end();
-            ++aitr)
-        {
-            //std::cout<<"Adding Parents Tile back in"<<std::endl;
-            aitr->pop_back();
-            _blackListedNodeSet.insert(aitr->back().second);
-            _tileMap.insert(TileMap::value_type(aitr->back().first,*aitr));
-        }
-        
-    }
-    while (!toRemoveList.empty());
-    
-
-#if 0
-
-    if ( !_blackListedNodeSet.empty() )
-        std::cout << "********** We have blacked list " << _blackListedNodeSet.size() << std::endl;
-
-    std::cout<<"TileMap contains "<<_tileMap.size()<<std::endl;
-    for(TileMap::iterator itr=_tileMap.begin();
-        itr!=_tileMap.end();
-        ++itr)
-    {
-        std::cout<<"    tile="<<itr->first.lod
-                 <<"  X="<<itr->first.x
-                 <<"  Y="<<itr->first.y<<std::endl;
-
-    }
-#endif
-
-}
 bool TileMapper::isTileNeighbourALowerLODLevel(const TileIdentifier& tid, int dx, int dy) const
 {
     if (_tileMap.count(TileIdentifier(tid.x+dx,tid.y+dy,tid.lod))!=0)
@@ -442,43 +165,13 @@ bool TileMapper::isTileNeighbourALowerLODLevel(const TileIdentifier& tid, int dx
         // not found tile in _tileMap, what should we do??
         // return true as a fallback right now.
 #if 0
-    std::cout << "TileMapper::isTileNeighbourALowerLODLevel() Not found tile in map," << std::endl;
-    std::cout << "    LOD=" << tid.lod << "  X=" << tid.x << "  Y=" << tid.y << std::endl;
+        std::cout << "TileMapper::isTileNeighbourALowerLODLevel() Not found tile in map," << std::endl;
+        std::cout << "    LOD=" << tid.lod << "  X=" << tid.x << "  Y=" << tid.y << std::endl;
 #endif
         return true;
     }
-
-    const TileStack& ts = itr->second;
-    
-    // note tile here, is tid's parent.
-    const TileStack::value_type* tile = (ts.size()>=1) ? &ts[ts.size()-1] : 0;
-
-    if (!tile)
-    {
-        // no tile, so must assume that neighbor is now at a lower level
-        return false;
-    }
-
-    // FIXME: this guy gives us wrong parent
-    // Nick 2010/12/12
-#if 0
-
-    // note parent here, is tid's parents parent.
-    const TileStack::value_type* parent = (ts.size()>=2) ? &ts[ts.size()-2] : 0;
-    
-    if (!parent)
-    {
-        // no parent so we must assume that is not at a lower level
-        return false;
-    }
-
-    const TileIdentifier& parent_tid = parent->first;
-#else
-
     TileIdentifier parent_tid(tid.x/2,tid.y/2,tid.lod-1);
-
-#endif
-
+    
     bool parentHasNorthNeighour = _tileMap.count(TileIdentifier(parent_tid.x,  parent_tid.y+1,parent_tid.lod))!=0;
     bool parentHasEastNeighour  = _tileMap.count(TileIdentifier(parent_tid.x+1,parent_tid.y,  parent_tid.lod))!=0;
     bool parentHasSouthNeighour = _tileMap.count(TileIdentifier(parent_tid.x,  parent_tid.y-1,parent_tid.lod))!=0;
@@ -486,55 +179,10 @@ bool TileMapper::isTileNeighbourALowerLODLevel(const TileIdentifier& tid, int dx
     
 
     // identify whether the tile is a NE/SE/SW/NW tile relative to its parent.
-
-        // FIXME: wrong parent wrong values
-        // Nick 2010/12/12
-#if 0
-    osg::Vec3 delta = tile->second->getBound().center() - parent->second->getBound().center();
-    
-    if (delta.y()>=0.0f) // noth side
-    {        
-        if (delta.x()>=0.0f)
-        {
-            // NE
-            if (dy==1)
-                return parentHasNorthNeighour;
-            else if (dx==1)
-                return parentHasEastNeighour;
-        }
-        else 
-        {
-            // NW
-            if (dy==1)
-                return parentHasNorthNeighour;
-            else if (dx==-1)
-                return parentHasWestNeighour;
-        }
-    }
-    else // south side
-    {
-        if (delta.x()>=0.0f)
-        {
-            // SE
-            if (dy==-1)
-                return parentHasSouthNeighour;
-            else if (dx==1)
-                return parentHasEastNeighour;
-        }
-        else
-        {
-            // SW
-            if (dy==-1)
-                return parentHasSouthNeighour;
-            else if (dx==-1)
-                return parentHasWestNeighour;
-        }
-    }
-#else
     osg::Vec3 delta(tid.x%2,tid.y%2,0);
-
+    
     if (delta.y()>0.0f) // noth side
-    {
+    {        
         if (delta.x()>0.0f)
         {
             // NE
@@ -571,7 +219,6 @@ bool TileMapper::isTileNeighbourALowerLODLevel(const TileIdentifier& tid, int dx
                 return parentHasWestNeighour;
         }
     }
-#endif
-
+    
     return false;
 }
diff --git a/src/osgPlugins/txp/TileMapper.h b/src/osgPlugins/txp/TileMapper.h
index 72fbc80dc..6d284e040 100644
--- a/src/osgPlugins/txp/TileMapper.h
+++ b/src/osgPlugins/txp/TileMapper.h
@@ -11,6 +11,10 @@
  * OpenSceneGraph Public License for more details.
 */
 
+/*    Dec 2010 - TileMapper was fixed and simplified
+    Nick
+*/
+
 #ifndef __TILEMAPPER_H_
 #define __TILEMAPPER_H_
 
@@ -96,7 +100,7 @@ public:
             
     virtual osg::Vec3 getEyePoint() const
     {
-	return getEyeLocal();
+        return getEyeLocal();
     }
     virtual float getDistanceToEyePoint(const osg::Vec3& pos, bool withLODScale) const;
     virtual float getDistanceFromEyePoint(const osg::Vec3& pos, bool withLODScale) const;
@@ -108,33 +112,13 @@ public:
     
     void insertTile(const TileIdentifier& tid);
     
-    bool canParentBeTraversed(const TileIdentifier& tid) const;
-    
-    void checkValidityOfAllVisibleTiles();
-    
-    bool containsBlackListedNodes() const
-    {
-        return !_blackListedNodeSet.empty();
-    }
-
-    inline bool isNodeBlackListed(const osg::Node* node) const
-    {
-        return _blackListedNodeSet.count(node)!=0;
-    }
-    
     bool isTileNeighbourALowerLODLevel(const TileIdentifier& tid, int dx, int dy) const;
     
 protected:
 
-    typedef std::vector< std::pair<TileIdentifier,osg::Node*> > TileStack;
-    typedef std::map< TileIdentifier, TileStack > TileMap;
-    typedef std::set< const osg::Node* > BlacklistedNodeSet;
-    
-    TileStack           _tileStack;
-    TileMap             _tileMap;
-    bool                _containsGeode;
-    
-    BlacklistedNodeSet  _blackListedNodeSet;
+    typedef std::map< TileIdentifier, int>        TileMap;
+    TileMap                                        _tileMap;
+    bool                                        _containsGeode;
     
 };