The Saints Row series does not have a good history when it comes to the holy PC. The port of Saints Row 2 was a buggy mess that could rightly be called an abomination. Saints Row the Third is better, but issues involving stutter and performance problems have been dogging the murder simulator since release. Volition has stated in the post on their forums that they have pinpointed the issues and are working with hardware manufacturers to fix the problem. The Saints Row forums has the story.