I have a single iMac with two accounts which point to a single iTunes library in the shared user folder. Worked fine. With the iTunes 9 update, it no longer works. Wife's account gets the message "iTunes library is locked" even though it's not open anywhere, and I've tried to reset permissions. Also, I've verified that the library is set for sharing and I've even deauthorized and reauthorized my account. Kind of out of ideas. Anyone have any thoughts?