This is a recent problem. Used to play this game no issue other then in game bugs. After the cut scenes to start the game the background of the screen becomes all solid blue for the main menu. The menu tabs as well as your characters abilities are all visible but your character is not. I tried to just play in a server but same issue. the HUD is still all visible including the mini map but your weopon or anything else in the game such as other players or the environment are not visible. My frames per sec have not dropped and nothing is overheating. Sound remains the same.

Intel Core i7 950 @ 3.07 GHz
6GB RAM
Dual Nvidia GTX 295s
Running on Vista 64 bit

Heres the image.
http://steamcommunity.com/profiles/76561198006732489/screenshot/541768102242510495?tab=public