i''ve been having some problems with my mac pro concerning the video card i guess. when i'm playing games like WOW it's like one model in the game will stick to another model, one of my friends said it was called tearing, i'm not sure what that is though. it's been happening for like 2 months now i guess, only when playing games though. Also, if i'm playing windowed and it starts happening i can full screen it and it temporarly fixes itself, and vice versa. i'm using the X1900 XT gfx card which i installed at a later date myself, but it used to work fine. Anything i can do to fix this? this is my first mac, would i be able to update the drivers or anything like that?