Apple released an updated version of iTunes 8 for Windows earlier today.
This latest version (available for XP, Vista and 64-bit systems) resolves a problem syncing Genius results to iPods and also addresses an issue where HDTV episodes were being deleted during download.
Other minor fixes are also included in this latest version.
The full download can be found at Apple's website here.
Note: Be sure and check the system requirements on the left side of the download page. Older systems or those not meeting 'most' of the list will probably experience some problems with iTunes 8.