If you installed the Multi-Plugin for iTunes 7 Preview, you have to uninstall it by replacing QuickTime.qts with the original one, or simply reinstalling iTunes or QuickTime.

Changes in version 2.5.0:
1. A LOT of bug fixes. I can’t event count them.
If Multi-Plugin didn’t work for you before, you should definately try it now.
2. Vista compatibility. Some features might still not work in Vista, but generally, it works.
3. Added iPod Hebrew support for all the iPods except the 2G iPod nano.
4. Added an option to allow downgrading iPod software.
5. Added Preview button in the Colorize dialog.
6. Many skins are included.