High Texture Setting = Major FPS Lag

[Netsky]

Well, I just got this game yesterday and was actually able to play it for quite some time without a problem. Then I started the game, and at the player selection screen, the FPS of the game dropped to somewhere around 1. After lots of trial and error work I came to the conclusion that it was the texture setting being on "High" that caused this. If the texture setting is on medium, there is no lag at all. This is not an issue caused by either of my graphics cards (Dual Nvidia 8800 GT), as I was playing it maxed out yesterday with no problem, or lag for that matter. So I tried reinstalling the game. That did nothing. I installed the patch. That didn't do anything either. Now I'm at a dead end. I would like to play the game maxed out, if at all possible. Do you have any suggestions as to what I should do?