iPod Sync - Help Please!

[Warrior Queen]

Since updating to the latest version of iTunes, I've been unable to properly synce my iPod (80g Classic). Stupidly I went for the full "restore iPod" option, wiped everything and now cannot re-sync. Tried it on a brand new computer (also with latest iTunes) and same thing happens. Managed to sync about 300 songs this morning (with another 5000 to go)but it will then "stall" on a particular track then freeze up. When it was actually syncing, it was unbelievably slow. I also have been getting the dreaded -69 error message, but there's nothing wrong with the music files as they loaded quite happily before the iTunes update.

We've tried all the usual re-boot, full restore, scan disc routes, all to no avail. Any suggestions please guys? I'm at screaming point, and I rely on this darned device to keep me sane when driving hundreds of miles every week!

Old laptop is running Windows XP, new PC has Vista.