Yah, try what Therm mentions with powertools to adjust timing, it was not needed on my system so I removed it. YMMV.
And as Idol mentions in his FAQ on this game it does run much more reliably in windowed mode. Full screen here the damn
game would crash on me 2 or more times a hour at the worst times, even with Idols GoTR pack fixes installed.
Windowed mode, I have managed to run 2 to 3 hours before a ill timed crash. I got so lazy in windowed mode I'd forget to save
as often as before. haha. All considering, in windowed mode it was reasonably stable on this machine, least thru about half way
into the game. I've yet to finish it yet.