Upgrading to Vista may result in the inability to play songs purchased from the online iTunes store and may corrupt your iPod.

Apple Computer is warning customers who use the Windows version of its iTunes software to hold off upgrading to Windows Vista until it can release a patch to fix a number of serious compatibility issues, one of which could result in a corrupt iPod player.

According to Apple, upgrading from Windows 2000 or Windows XP to Vista may result in the inability to play songs purchased and downloaded to the desktop iTunes player from its online iTunes store. Even worse, users that eject their digital music player from a desktop port using the “Safely Remove Hardware” could corrupt their iPods.

Apple says the safe way to undock an iPod from a Vista-equipped PC, until a patch is released, is to be sure and use the “Eject iPod” control in the iTunes software.

The company recommends against upgrading to Vista at this time. Apple expects to fix the issues with the next version of iTunes “within a few weeks.”

Here’s the text of Apple’s statement on compatibility with Vista:

Compatibility with Windows Vista

Apple is preparing to address a number of iTunes compatibility issues in the next release of the software.

Some currently known compatibility issues with iTunes 7.0.2 and earlier versions include:

• iTunes Store purchases may not play when upgrading to Windows Vista from Windows 2000 or XP.
• iPod models with the “Enable Disk Use” option turned off may be unable to update or restore iPod software, and make changes to iPod settings.
• iPod models configured to Auto Sync and have the “Enable Disk Use” option turned off may require being ejected and reconnected to resync.
• Ejecting an iPod from the Windows System Tray using the “Safely Remove Hardware” feature may corrupt your iPod. To always safely eject an iPod, choose Eject iPod from the Controls menu within iTunes.
• Cover Flow animation may be slower than expected.
• Contacts and calendars will not sync with iPod.

Upgrading to Windows Vista

If you are upgrading from Windows XP or 2000 to Windows Vista prior to the next release of iTunes, here are a few steps that will improve your experience when syncing your iPod or playing iTunes Store purchases once upgraded to Windows Vista.

1. Deauthorize all iTunes Store accounts.
2. Enable Disk Use on all iPod models.
3. Uninstall iTunes.
4. Perform a clean install of Windows Vista (Highly recommended but not required).
5. Reinstall the latest version of iTunes.
6. Open iTunes.
7. Choose Authorize Computer from the Store menu in iTunes.

Customers who have upgraded to Windows Vista and are still experiencing issues playing iTunes Store purchases should download and run the iTunes Repair Tool for Vista after re-installing iTunes 7.0.2.