There are various lists of missing or incorrect information in the ZIP inventory database linked on the left pane. These is mainly for the use of the ZIP people to update things - it isn't meant to suggest that there are any major problems with their database! There are separate links to lists of titles missing from ZIP's database, and those that are still on order.

Website Bug #1 - Users of Apple's Safari web browser cannot mark discs as returned on the ZipList page, since the calendar does not pop up when you click on the icon.