That's so strange...
I hope Andrei can help you with this, but I don't see any other post reporting the problem you have. I can't think of anything else resonable to try...

Have you tried to start with a new database? Don't delete your old one, just select database close, then database new and try adding one of your problem cd's. You shouldn't have to, but I'd bet Andrei would be curious of that made a difference. If you current database is somehow corrupt that may be the cause, but don't know.

Fred