So far it's only happened when I have been in a game and not in the chat channels. My screen will become very pixelized and these pixels will start flashing colors randomly. There will also be grey/black pixelated vertical lines across the screen. I can still see a little bit such as the blurred outline units/map/type but for the most part it's just the flashing pixels. My sound is completely uneffected by this and continues on as normal. I can still remain in the game and play sort of(cant see)but if I alt + tab of if I exit the Starcraft application my entire screen just turns blue (sound still works).
Once this happens I turn off my computer at the back and then restart it no problem. It just happens randomly, and it ONLY happens with starcraft.
I dont know if it is relevent at all but I am currently running Windows Vista 64 bit. Please help it makes playing starcraft nearly impossible