This bug bit close to home - suddenly iTunes 9 on my iMac would start skipping in the middle of a song - jumping ahead 30 seconds or so, play a little bit, and then skip some more. If there were multiple songs in the playlist, iTunes would skip to the next song. It did this for most songs and podcasts, but not all. While researching what could be wrong - iTunes 9.2 was released. During the upgrade, iTunes rebuilt my music library. Between the two (and I suspect it was rebuildling the library) ITunes is back in working order. (In fact, I'm listening to some Grateful Dead while writing this.)