Lost Album and Artist info in iTunes

Not sure what happened. I synced my iPod this morning, 4/25/2008, and seemed to have lost the ability to sort by Album or Artist in iTunes. The Song names and Album Artwork are there but the Album and Artist names are missing. I've looked in my iTunes Library and it's the same story. I've noticed other folks missing all their play lists and there seems to be help for them. What about this? It's frustrating not to be able to sort by Album or Artist.