More people have this problem, the answer i dont know.
I myself have it to moost of the time happens in the 1-15 PvP zone.
Start off with mobs being all white with no textures, then player names start to dissapear and end up crashing back to my desktop
All i know know its not a driver problem and it affects both ATI and Nvidia cards.
Sometimes i can be in pvp for 4 hours without no problems, and the other time it happens after 30 minutes.