ITunes 9.0.2 locks trying to sync iPod nano under Windows 7 Enterprise x64

Question

I've been fighting this thing for a couple weeks now and it's getting to be very frustrating. I wanted to sync some new music purchases onto my various iPods, but ended up with a 5G iPod Video with just a couple songs on it and which refused to sync. It had been fine before I tried to sync it, with about 45GB of music on it, but now I couldn't get it to work at all. I formatted it, I ran chkdsk, I restored it, but nothing I did would make it sync. I thought the hard drive was fried, so I ordered a new 160GB Classic. After I got it, I found that it did the same thing! iTunes would simply hang trying to sync to it and it would never get more than a couple songs on there before giving up.
What it would do is spin for a couple minutes and then lock up completely. If it was playing a song, it would finish the song but then not go to the next one and just stop. I couldn't bring it up, I couldn't click on it, I couldn't close it. I couldn't even end the task in Task Manager. Even ejecting the drive in Windows didn't make a difference. The only way to get it back was to unplug the iPod. Then iTunes would come back and I could use it again.
Finally, I uninstalled iTunes and reinstalled it, and then both the new Classic and the old Video were able to sync with no problems. I can't tell you how happy I am to have spent that $235 for no good reason!
So next I grabbed my 3G Nano and tried to sync it. No dice, same problem. So I tried all the same things, check for errors, format, restore. All of this was much quicker since it's only 8GB of flash instead of a 60GB hard drive, but still none of it worked. Finally I installed iTunes on my work laptop running Windows XP, imported the iTunes library from my other machine (via .xml), and waited. And waited. And waited. It takes a long time to rebuild the library from that xml file! When it was done, I plugged the Nano into the XP laptop and restored it... and it synced! Like it was nothing at all. Everything went on there quickly and with no fuss.
Now, this is the same content, my music is on a network drive. So there is no difference whatsoever in what was being synced. The only difference is the PC being used.
So, what the heck! I do need to get iTunes working on my primary machine again, as this is the machine I use. I can't depend on my work laptop to sync the Nano since I'd have to re-import the entire library every time to get the changes I've made. Is there some known issue with Windows 7 x64 and iTunes 9.0.2? This used to work just fine! Please, if anyone has any suggestions I could really use some relief.
Thanks!!

Answer 1

Doublechecking something Emcee. I see you've got Windows 7 x64, so I'm assuming you've got at least 4 GB of RAM. Do you also have an NVIDIA USB EHCI chipset on that PC? If so, see the following Microsoft document:
[You encounter problems when you move data over USB from a Windows 7 or Windows Server 2008 R2-based computer that has an NVIDIA USB EHCI chipset and at least 4GB of RAM|http://support.microsoft.com/kb/976972]