This isn't an issue anymore, nowadays there are MMUs which isolate shaders from memory they aren't supposed to touch.
OP's problem stems from the fact that some video buffer used by his browser hasn't been cleared after deallocation. At some later time this buffer either has been erroneously displayed instead of the game's buffer or has been allocated to the game which erroneously displayed it without filling with new content.
OP's problem stems from the fact that some video buffer used by his browser hasn't been cleared after deallocation. At some later time this buffer either has been erroneously displayed instead of the game's buffer or has been allocated to the game which erroneously displayed it without filling with new content.