i had the same issue back with my VGA which was a GTX480 the game would simply not brake through the 40-50FPS barrier no matter what, then in an unfortunate accident my VGA overloaded and died and i replaced it with a HD5870 which is the ATI card. The very first thing i noticed when i logged in with that card (with turned VSync off) was that the game was shooting off 250-300FPS but that was while flying while fighting or raiding i get about 80fps.
So not sure if that is what the issue might be for you mine was the graphic card