I just got this game recently, and it stutters to the point that it is unplayable. It runs perfectly for a while, but then will freeze/drastically stutter for a few seconds here and there for seemingly no reason at all. The game never crashes however.

Video: http://www.youtube.com/watch?v=W55fjOsAB1A

My specs are:
Memory: 3.2 GB RAM
Video Card: ATI Radeon HD 3600 series (512 MB)
Processor: AMD Phenom 8650 Triple-Core Processor

If anyone knows any fixes, that would be great. Thanks.