I installed Ubuntu 10.04 last night but I doubt that has anything to with it as iTunes worked fine this morning. But about half an hour ago I opened iTunes and it had lost most of my settings and it had to rebuild my library. I had to manually add all of my apps and fix a few settings. I still have my playlists, except most of my genious ones have vanished. I also still have all my iPod backups. Has anyone else had this happen?