My guess is you have accidentally set the transfer mode for the lower third layer to Dissolve (this is pretty easy to do with the keyboard shortcut by holding the Shift key and tapping – or =). Change it back to Normal.
OpenGL is fine for interactive previews, but I heartily recommend leaving it off for anything else, and especially leaving it off for renders. From Render with OpenGL [link]:
Important: Because not all features of a composition can be rendered with OpenGL—and because some features that can be rendered with OpenGL are rendered with different results—you may only want to use OpenGL rendering to accelerate previews and to provide faster rendering for non-final results.
The OpenGL renderer is gone in CS6 (and good riddance, if you ask me).
Walter Soyka
Principal & Designer at Keen Live
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