diff --git a/include/osgDB/DatabasePager b/include/osgDB/DatabasePager
index 379127759..cfb67c68f 100644
--- a/include/osgDB/DatabasePager
+++ b/include/osgDB/DatabasePager
@@ -138,6 +138,9 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         ThreadPriority getThreadPriorityOutwithFrame() const { return _threadPriorityOutwithFrame; }
         
         
+        /** Get the number of frames that are currently active.*/
+        int getNumFramesActive() const { return _numFramesActive; }
+
         /** Signal the database thread that the update, cull and draw has begun for a new frame.
           * Note, this is called by the application so that the database pager can go to sleep while the CPU is busy on the main rendering threads. */
         void signalBeginFrame(const osg::FrameStamp* framestamp);
@@ -261,6 +264,13 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
             _databasePagerThreadBlock->set(
                 (!_fileRequestList.empty() || !_childrenToDeleteList.empty()) && !_databasePagerThreadPaused);
         }
+        
+        inline void updateFrameBlock(int delta)
+        {
+            OpenThreads::ScopedLock<OpenThreads::Mutex> lock(_numFramesActiveMutex);
+            _numFramesActive += delta;
+            _frameBlock->set(_numFramesActive==0);
+        }
 
 
         /** Iterate through the active PagedLOD nodes children removing 
@@ -277,6 +287,8 @@ class OSGDB_EXPORT DatabasePager : public osg::NodeVisitor::DatabaseRequestHandl
         bool                            _databasePagerThreadPaused;
     
         bool                            _useFrameBlock;
+        int                             _numFramesActive;
+        mutable OpenThreads::Mutex      _numFramesActiveMutex;
         osg::ref_ptr<Block>             _frameBlock;
         int                             _frameNumber;
 
diff --git a/src/osgDB/DatabasePager.cpp b/src/osgDB/DatabasePager.cpp
index 6a5a4f805..cc82ba238 100644
--- a/src/osgDB/DatabasePager.cpp
+++ b/src/osgDB/DatabasePager.cpp
@@ -28,6 +28,7 @@ DatabasePager::DatabasePager()
     _databasePagerThreadPaused = false;
     
     _useFrameBlock = false;
+    _numFramesActive = 0;
     _frameNumber = 0;
     _frameBlock = new Block;
     _databasePagerThreadBlock = new Block;
@@ -236,20 +237,18 @@ void DatabasePager::signalBeginFrame(const osg::FrameStamp* framestamp)
         
     } //else osg::notify(osg::INFO) << "signalBeginFrame >>>>>>>>>>>>>>>>"<<std::endl;
 
+    updateFrameBlock(1);
 
-    _frameBlock->reset();
-
-    if (_threadPriorityDuringFrame!=getSchedulePriority())
+    if (_numFramesActive>0 && _threadPriorityDuringFrame!=getSchedulePriority())
         setSchedulePriority(_threadPriorityDuringFrame);
-
 }
 
 void DatabasePager::signalEndFrame()
 {
     //osg::notify(osg::INFO) << "signalEndFrame <<<<<<<<<<<<<<<<<<<< "<<std::endl;
-    _frameBlock->release();
+    updateFrameBlock(-1);
 
-    if (_threadPriorityOutwithFrame!=getSchedulePriority())
+    if (_numFramesActive<=0 && _threadPriorityOutwithFrame!=getSchedulePriority())
         setSchedulePriority(_threadPriorityOutwithFrame);
 
 }