diff --git a/src/osgPlugins/txp/TXPNode.cpp b/src/osgPlugins/txp/TXPNode.cpp
index a80e70b9e..acadf54a1 100644
--- a/src/osgPlugins/txp/TXPNode.cpp
+++ b/src/osgPlugins/txp/TXPNode.cpp
@@ -90,6 +90,8 @@ void TXPNode::traverse(osg::NodeVisitor& nv)
     {
     case osg::NodeVisitor::CULL_VISITOR:
     {
+
+        OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
                 
         osgUtil::CullVisitor* cv = dynamic_cast<osgUtil::CullVisitor*>(&nv);
         if (cv)
@@ -132,8 +134,12 @@ void TXPNode::traverse(osg::NodeVisitor& nv)
         break;
     }
     case osg::NodeVisitor::UPDATE_VISITOR:
+    {
+        OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_mutex);
+
         updateSceneGraph();
         break;
+    }
     default:
         break;
     }
diff --git a/src/osgPlugins/txp/TXPNode.h b/src/osgPlugins/txp/TXPNode.h
index ba73a65f8..ad82f6bcc 100644
--- a/src/osgPlugins/txp/TXPNode.h
+++ b/src/osgPlugins/txp/TXPNode.h
@@ -93,6 +93,8 @@ protected:
     std::string                     _archiveName;
     std::string                     _options;
     
+    OpenThreads::Mutex              _mutex;
+    
     osg::ref_ptr<TXPArchive>        _archive;
     osg::ref_ptr<TXPPageManager>    _pageManager;