Unplayable

[fmgt98]

I'm just bumping this post back up as I still cannot play the game. I'm sure there are others as well. I have tried everything I can think of to no avail.

Things I have tried.

1. New Drivers
2. Uninstall and reinstall (Game was origiinally installed on my 2nd hard drive, on drive E but reinstalled to drive C:
3. Updated Direct X 9
4. Cleared the game cache as suggested in a previous post.
5. Played other games to verify there was no issue with them (There wasn't) Can play Unreal Tournament 2K4 on highest settings with no issue at all
6. Tried many different in game settings. (Even went down to lowest graphical settings) This created a slight performance increase but I shouldn't have to play the game at that setting.

Things I have noticed.

1. When the game first started it was kind of laggy, especially when seeing zombies.
2. Walking in halls, the game sputtered.
3. When I first wore the gas mask the game was playable but I noticed that caused additional lag. (Not sure if the lag was due to the gases or the gas mask itself.)
4. As the game progresses, the lag gets worse. Now when coming across zombies its unplayable as the frame rate appears to go down to 1 or 2 fps. Once again i ask, is there a way to check fps in this game?

Those are basic observations. I can provide additional information if requested. Please address this issue as I know I am not the only one experiencing this and I really would like an opportunity to finish the game.
4.