diff --git a/include/osgShadow/MinimalShadowMap b/include/osgShadow/MinimalShadowMap
index 3612fd133..52d915784 100644
--- a/include/osgShadow/MinimalShadowMap
+++ b/include/osgShadow/MinimalShadowMap
@@ -95,13 +95,14 @@ class OSGSHADOW_EXPORT MinimalShadowMap : public StandardShadowMap
         osg::Matrix                        _modellingSpaceToWorld;
         float                              _maxFarPlane;
         float                              _minLightMargin; 
-        ShadowReceivingCoarseBoundAccuracy _shadowReceivingCoarseBoundAccuracy;
+        ShadowReceivingCoarseBoundAccuracy _shadowReceivingCoarseBoundAccuracy;        
 
         struct OSGSHADOW_EXPORT ViewData: public BaseClass::ViewData
         {
             osg::Matrix                      *_modellingSpaceToWorldPtr;
             float                            *_maxFarPlanePtr;
             float                            *_minLightMarginPtr;
+            int                               _frameShadowCastingCameraPasses;
 
             ConvexPolyhedron                 _sceneReceivingShadowPolytope;
             std::vector< osg::Vec3d >        _sceneReceivingShadowPolytopePoints;
diff --git a/include/osgShadow/ProjectionShadowMap b/include/osgShadow/ProjectionShadowMap
index 4ca928195..44d807c9b 100644
--- a/include/osgShadow/ProjectionShadowMap
+++ b/include/osgShadow/ProjectionShadowMap
@@ -65,9 +65,12 @@ class OSGSHADOW_EXPORT ProjectionShadowMap : public MinimalBoundsBaseClass
             virtual void frameShadowCastingCamera
                 ( const osg::Camera* cameraMain, osg::Camera* cameraShadow, int pass = 1 )
             {
-                // Force dependent name lookup
-                ShadowProjectionAlgorithmClass::operator()
-                    ( &this->_sceneReceivingShadowPolytope, cameraMain, cameraShadow );
+                if( pass == BaseClass::ViewData::_frameShadowCastingCameraPasses - 1 )
+                {
+                    // Force dependent name lookup
+                    ShadowProjectionAlgorithmClass::operator()
+                        ( &this->_sceneReceivingShadowPolytope, cameraMain, cameraShadow );
+                }
 
                 // DebugBoundingBox( computeScenePolytopeBounds(), "ProjectionShadowMap" );
                 BaseClass::ViewData::frameShadowCastingCamera( cameraMain, cameraShadow, pass );
diff --git a/src/osgShadow/ConvexPolyhedron.cpp b/src/osgShadow/ConvexPolyhedron.cpp
index 217d2a46c..7f995d024 100644
--- a/src/osgShadow/ConvexPolyhedron.cpp
+++ b/src/osgShadow/ConvexPolyhedron.cpp
@@ -31,7 +31,16 @@ using namespace osgShadow;
 
 
 #if defined( DEBUG ) || defined( _DEBUG ) || defined( _DEBUG_ )
-    #define MAKE_CHECKS 1
+// ConvexPolyhedron may produce tons of warnings when it becomes non convex.
+// Unfortuantely this condition often happens in daily routine of shadow usage 
+// due precision errors mixed with repeating frustum cuts performed by MinimalShadowClasses.
+// However, in most of above cases this condition is not fatal
+// because polyhedron becomes concave by very small margin (mesuring deep the hole).
+// Unfortunately warnings are produced even for such small margin cases and can 
+// easily flood the console.
+// So I leave MAKE_CHECKS commented out. Its really useful only for a guy who debugs 
+// larger concaveness issues which means most developers will want to keep it commented.
+//    #define MAKE_CHECKS 1
 #endif
 
 #if MAKE_CHECKS
diff --git a/src/osgShadow/DebugShadowMap.cpp b/src/osgShadow/DebugShadowMap.cpp
index a6e0785f3..37f73878d 100644
--- a/src/osgShadow/DebugShadowMap.cpp
+++ b/src/osgShadow/DebugShadowMap.cpp
@@ -391,8 +391,25 @@ void DebugShadowMap::ViewData::init( ThisClass *st, osgUtil::CullVisitor *cv )
 
     _hudSize                  = st->_hudSize;
     _hudOrigin                = st->_hudOrigin;
-    _viewportSize             = st->_viewportSize;
+
     _viewportOrigin           = st->_viewportOrigin;
+    _viewportSize             = st->_viewportSize;
+
+    osg::Viewport * vp = cv->getViewport();
+    if( vp )
+    {
+        // view can be a slave that covers only a fraction of the screen
+        // so adjust debug hud location to proper viewport location 
+        _viewportOrigin[0] += vp->x();
+        _viewportOrigin[1] += vp->y();
+
+        if( _viewportSize[0] > vp->width() - _viewportOrigin[0] )
+            _viewportSize[0] = vp->width() - _viewportOrigin[0];
+
+        if( _viewportSize[1] > vp->height() - _viewportOrigin[1] )
+            _viewportSize[1] = vp->height() - _viewportOrigin[1];
+    }
+
     _orthoSize                = st->_orthoSize;
     _orthoOrigin              = st->_orthoOrigin;
     
diff --git a/src/osgShadow/MinimalCullBoundsShadowMap.cpp b/src/osgShadow/MinimalCullBoundsShadowMap.cpp
index 2a93705c4..c00769bf3 100644
--- a/src/osgShadow/MinimalCullBoundsShadowMap.cpp
+++ b/src/osgShadow/MinimalCullBoundsShadowMap.cpp
@@ -41,6 +41,7 @@ void MinimalCullBoundsShadowMap::ViewData::init
     ( ThisClass *st, osgUtil::CullVisitor *cv )
 {
     BaseClass::ViewData::init( st, cv );
+    _frameShadowCastingCameraPasses = 2;
 }
 
 void MinimalCullBoundsShadowMap::ViewData::aimShadowCastingCamera
diff --git a/src/osgShadow/MinimalDrawBoundsShadowMap.cpp b/src/osgShadow/MinimalDrawBoundsShadowMap.cpp
index c1a49ee79..4589d6c44 100644
--- a/src/osgShadow/MinimalDrawBoundsShadowMap.cpp
+++ b/src/osgShadow/MinimalDrawBoundsShadowMap.cpp
@@ -271,6 +271,7 @@ void MinimalDrawBoundsShadowMap::ViewData::init
 {
     BaseClass::ViewData::init( st, cv );
     
+    _frameShadowCastingCameraPasses = 2;
     _camera->setCullCallback
         ( new CameraCullCallback( this, _camera->getCullCallback() ) );
     
diff --git a/src/osgShadow/MinimalShadowMap.cpp b/src/osgShadow/MinimalShadowMap.cpp
index 5f31ba65c..4170563bb 100644
--- a/src/osgShadow/MinimalShadowMap.cpp
+++ b/src/osgShadow/MinimalShadowMap.cpp
@@ -168,7 +168,7 @@ void MinimalShadowMap::ViewData::aimShadowCastingCamera
     osg::Matrix mvp = _camera->getViewMatrix() * _camera->getProjectionMatrix();
     cutScenePolytope( osg::Matrix::inverse( mvp ),  mvp );
 
-    MinimalShadowMap::ViewData::frameShadowCastingCamera
+    frameShadowCastingCamera
             ( _cv->getRenderStage()->getCamera(), _camera.get(), 0 );
 }
 
@@ -207,7 +207,7 @@ void MinimalShadowMap::ViewData::frameShadowCastingCamera
         // space (-1..1), it may get "twisted" by precisely adjusted shadow cam 
         // projection in second pass. 
 
-        if ( pass == 0 ) 
+        if ( pass == 0 && _frameShadowCastingCameraPasses > 1 )
         { // Make sure extruded polytope does not extend beyond light frustum
             osg::Polytope lightFrustum;
             lightFrustum.setToUnitFrustum();
@@ -304,6 +304,8 @@ void MinimalShadowMap::ViewData::init( ThisClass *st, osgUtil::CullVisitor *cv )
     _modellingSpaceToWorldPtr = &st->_modellingSpaceToWorld;
     _minLightMarginPtr        = &st->_minLightMargin;
     _maxFarPlanePtr           = &st->_maxFarPlane;
+
+    _frameShadowCastingCameraPasses = 1;
 }
 
 void MinimalShadowMap::ViewData::cutScenePolytope