[motmotmot]

After upgrading my jailbroken and unlocked iPhone 2G from 1.1.4 to 2.2.1 with pwnage tool and transferring back the backed-up data, I could not access my music. The music was on the device and in the correct folders, but not visible to the iPod application.

I've tried searching forums for a solution, but nothing worked. All I could find is that people recommend creating a new user and not using a backed-up user once setting up the iPhone after the upgrade - a hassle I wanted to avoid.

I've already given up all hope and just fiddled around with my iPhone. And then, while going through the advanced features of BossPrefs I've found 'Fix User Dir Permissions' button and decided to give it a try. It turned out it made my music available again.

If this solution has already been posted, sorry for double-posting.