Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00000018
osgUtil::RenderStage::draw (this=0x2d9a75f0, renderInfo=@0x235135c0, previous=@0xbffff048) at /Users/lfugal/src/fg/OpenSceneGraph/include/osg/ref_ptr:47
47                  if (_ptr==ptr) return *this;
(gdb) bt
#0  osgUtil::RenderStage::draw (this=0x2d9a75f0, renderInfo=@0x235135c0, previous=@0xbffff048) at /Users/lfugal/src/fg/OpenSceneGraph/include/osg/ref_ptr:47
#1  0x1426ecc4 in osgUtil::RenderStage::drawPreRenderStages (this=0x0, renderInfo=@0x235135c0, previous=@0xbffff048) at /Users/lfugal/src/fg/OpenSceneGraph/src/osgUtil/RenderStage.cpp:207
#2  0x1428f2b8 in osgUtil::SceneView::draw (this=0x24a54f90) at /Users/lfugal/src/fg/OpenSceneGraph/src/osgUtil/SceneView.cpp:1352
#3  0x000082e4 in FGRenderer::update (refresh_camera_settings=true) at renderer.cxx:577
#4  0x00037974 in GLUTdraw () at fg_os.cxx:128
#5  0x97e12438 in -[GLUTView drawRect:] ()
#6  0x97e122e4 in -[GLUTView handleWorkEvent:] ()
#7  0x97e2b61c in processWindowWorkList ()
#8  0x97e2b684 in __glutProcessWorkEvents ()
#9  0x97e1b1d8 in -[GLUTApplication run] ()
#10 0x97e2b954 in glutMainLoop ()
#11 0x00005218 in fgMainInit (argc=2, argv=0xbffffb70) at main.cxx:1071
#12 0x00003840 in main (argc=2, argv=0xbffffb70) at bootstrap.cxx:220