Now I've changed the clear canvas function. Hope it could work.
Still the same
I don't have the problem at work, also win 8.1 + latest chrome (beta actually). Switched to chrome beta at home as well, but it had no effect.
FWIW: with my win8.1 install (when the problem started) also came new hardware. I'm now using an Intel CPU (i7 4790). VGA is the same (AMD R290X).