I have been running iTunes on Vista for the past 3 months and everything has been fine except that iTunes will crash from time to time.  It would never screw up my library.  I even bought a new 80 gig iPod a couple of weeks ago so that I can watch some movies and video podcasts while I work.

Anyway, I woke up this morning to get my iPod ready for my trip to a client.  I start my desktop machine, it automatically starts iTunes because my iPod is docked and poof...my library is all screwed up.  My songs are all there except for all my purchases.  My podcast subscriptions are gone.  Movies, gone. Games, gone.  It sucks because now I have to deal with support to get my purchases back and then I have to set up all my movies, podcasts, and games.  I don't get it.  iTunes has been running good for the past 3 months.  Who said Apple can't write horrible software?