osgViewer::ScreenCaptureHandler not working with osgQt

[blobfish]

I have taken the osgviewerQt example and added a osgViewer::ScreenCaptureHandler. When I take the screen capture I get an error. "Warning: detected OpenGL error 'invalid operation' at end of SceneView::draw()" and the output picture is corrupted. I can turn off the samples via QSurfaceFormat I get a valid picture but still have the error. I have turned on all various levels of OSG_NOTIFY and haven't got any clues. I ran it through apitrace and didn't see anything, but I my opengl knowledge is pretty low so that might not mean anything. I have tested with just osg and I can't duplicate the problem. Any hints on what Qt might be doing that ScreenCaptureHandler doesn't like? Thanks.