I get something similar to the previous post, with slowdown, except mine never freezes. What happens with my game is that it slows down for a long time, speed up for a second or two (faster than normal) and then resumes for a little while on normal speed, and then becomes really slow again.
I have a Dell Labtop
2 ghz Processor
NVidia GeForce Go5200 series GPU
512 RAM
Microsoft XP pro
Help please, the game is hardly playable with this kind of jostling speed of game!!