SH3 using 95+% Cpu? major stuttering. unplayable! help!

[Demo]

Hello, first post here. long time lurker.

Well here is my problem. When i first installed SH3 it ran perfectly fine the first time. (w 1.4 patch) Then i got greedy and installed gwx and that ran fine the first time i ran it. but then on my second time running the game when i got the the main menu it was a stuttering piece of ****. it was using 85-100% cpu even just moving the mouse around the menu. So I uninstalled the game completely (did the regedit and starforce removal too) and reinstalled and repatched. (no gwx this time) However when i tried to run the game this time it would crash when it tried to play the intro movies. how do i know that you ask? well after spending hours on various forums I found out the some people had problems with the intro movies and so i moved them to a backup folder. Now the game loads fine except i still have the major stuttering/cpu useage problem making the game unplayable.

I exceed the recommended specs so i don't think it is that. My suspicion is it is something maybe with the bink video thing because of the intro movie crashes. I have tried uninstalling completely and reinstalling several times now with the same result. overwhelming cpu usage making the game unplayable. I am at wits end and am considering writing the game off at this point. any ideas?

Specs- 2.4ghz P4
1.5gb ram
BFG nvidia 6600 with latest drivers
Windows xp sp2