This posting is older than 6 months and can contain outdated information.
Here's a possible solution I received from a power user.
The problem seems to stem from a defective "iTunes Library" file and
rebuilding it has solved the problems for that user.
WARNING:
Follow the instructions fully at your own risk. Smart Playlists can
possibly be turned into regular ones. I haven't tried out the solution
myself, yet, though. Making a copy of your iTunes Library and iTunes
media files certainly can't hurt.
Instructions to rebuild your iTunes Library:
1) Quit iTunes.
2) Go to ~/Music/iTunes and rename "iTunes Library" to f.ex. "iTunes
Library (Old)"
3) Start iTunes.
4) Choose "Import Library" from the File menu.
5) In the dialog now opening, choose the file "iTunes Music
Library.xml" located in ~/Music/iTunes/
6) Wait for iTunes to complete rebuilding your library cleanly from
scratch.
7) Restart iTunes.
If you try out this solution, please share the result here. Thanks!
Best regards,
Felix Schwarz
