Guitar Hero Aerosmith never fails to fall out of sync

I'm a big guitar hero fan and when GH3 came out for the PC, I was overjoyed, and it plays like a dream so when Guitar Hero Aerosmith came out for the PC, I thought, sweeeeeet! Well, it looks sweet, sounds sweet. Doesn't play so sweet, even though my framerates are totally thru the roof with my GeForce GTS 250 and Core2 Duo E8400 combination.

The problem is, when I click to play a song, it starts out playing beautifully, but almost note by note, I can feel the notes drifting farther and farther away from the music. By the end of any song, I'm playing notes seconds after I hear them. Playing on easy and maybe medium, this isn't too much of a problem, but playing on hard and expert as I do, it really throws you off! I've had these issues under Windows Vista no matter which version I was using.

My specs include:
Gigabyte GA-EP45-DS3R motherboard
Intel Core2 Duo E8400 (3.0 GHz)
8 GB DDR2-800 RAM
Gigabyte GeForce GTS 250 (1 GB) (Previously, Gigabyte GeForce 8600 GT 256 MB GDDR3)
Realtek HD Audio (Azalia)
2x 80 GB 7200 RPM hard drives
500 GB WD MyBook eSATA external
Windows Vista Home Premium

I should add that I keep getting the speech from Aspyr that the game isn't 64 bit compatible, but that point is moot. I encounter the same exact issue whether I use 32 bit or 64 bit. I have used two different video cards. Same effect on each one! Also, I should add, there was ONE way I managed to get the game to work without falling out of jive. Unfortunately, that method involves Windows 7. Running Windows 7, I did not encounter these issues whether running 32 bit or 64 bit! Now I would just switch to using the Windows 7 Beta all the time since it actually works, BUT, like anybody with half a brain always mentions, it's a prerelease OS, it's gonna expire, and of course, it'll cost a mint. I really hope I can solve this issue without having to resort to a new OS because it's really pissing me off.