All SDL applications that use OpenGL result in blue output with the 304.30 drivers. An image is still there, but pretty much the only thing you get are different shades of blue (sort of a "blue and white" analogue of "black and white".) This has been confirmed by other people as well: http://phoronix.com/forums/showthread.php?72611-NVIDIA-304-30-Supports-FXAA-X-Server-1-13-K10&p=278430#post278430 Might be worth masking these again? Dunno.
304.30 isn't even in the tree, nor was I intending they ever be added to the tree. Where exactly are you seeing them come from?
Oops, sorry. Got my overlays confused :-/