I have an Intel Core Duo processor, and like some of you, I had serious audio/video sync problems. After a lot of looking around, I found this Microsoft Support Article:

http://support.microsoft.com/?id=896256

I installed the hotfix mentioned there, and all my synching issues are fixed. The game runs absolutely perfectly now.

If you have a multi-core processor, and just cannot seem to get this problem solved, give this hotfix a try. It's not public yet, so you'll have to give Microsoft a call to get the hotfix for free. (Or google for it, but uh, you didn't hear that from me.)

NOTE: This solution is only for people with a multi-core processor!

Thanks mistershrubber, I'll refer people to your solution if anyone else is having the same problem with their Intel Core Duo.

Thank you mistershrubber!

This worked perfectly on my Conroe 6400

No more sync problems.

By the way the link for this hotfix is now listed on that page and available for download.

For AMD dual-core users, there is a official AMD fix at [URL=http://www.amd.com/us-en/assets/content_type/utilities/AMD_Dual-Core_Optimizer_113.zip]. It solved the problem for me instantly. All the other solutions failed. I hope it helps others too.