From the official changelog:
iTunes 9.0.3 provides a number of important bug fixes, including:
- iTunes no longer ignores your “Remember password for purchases” setting;
- Addresses problems with syncing some Smart Playlists and Podcasts with iPod;
- Resolves a problem recognizing when iPod is connected.
- Addresses issues that affect stability and performance.
Available through software update, fixes one of the most annoying bugs ever.