Found this article on Drudge.
It claims some have found that songs bought on its iTunes Store will not play on the new system, and that other Vista users have even seen their iPods corrupted when they try to unplug them. The contacts and calendar functions on iPods are also said to be affected.
A statement on Apple's website reads: "iTunes Store purchases may not play when upgrading to Windows Vista from Windows 2000 or XP.
Bill Gates & Steve Jobs need a group hug.