I recently bought an iPod nano and wanted to use it with my laptop. The laptop is running a fully updated Ubuntu 5.10, and I book into Windows 2000 (Service Pack 4 also fully updated) using VMWare 5.51 (build 19175) which is quite capable of virtualizing the CD-ROM drive (for ripping) and USB (for syncing to the iPod). I have iTunes 188.8.131.52 installed.
But the syncing didn't work.
When I plugged the iPod nano with VMWare having focus, I would get a warning that VMWare was going to have to take the iPod nano away from usb_storage (the Linux module that will happily mount an iPod as a hard disk). Even though VMWare claimed to do this (and the iPod was no longer mounted in Ubuntu) it didn't work. The iPod was not visible in iTunes or in My Computer.
The solution is very simple:
1. Start VMWare, boot Windows, load iTunes
2. In a Ubuntu shell type 'sudo rmmod usb_storage'
3. Go straight back to VMWare and full screen the VM
4. Plug iPod into USB port
This works for me everytime. As long as usb_storage doesn't get to see the iPod it'll sync without a problem.