WoW Bug/Glitch?

Having some random WoW bugs when I log into my Char screen and into the game. Basically the whole character just turns pitch black, except my guild tabard and hair. It's nothing big, but its really annoying to have to restart the game. And while talking about random bugs, whats with random checkered boxes on the characters head and stuff? Kind of strange running around with a checkered box on my head, eh?

I've seen this on my setup a long time ago... it was related to my drivers back then.

Also, other people with similar problem (although much worse) have issues like this when their GPU overheats..

Check the temps, but if this happens when you log in (meaning GPU didn't really have time to overheat yet), then it might be drivers issue.