iTunes Error 1150 while syncing music on iPhone

Hello all.

I'm a developer,i've downloaded iOs 5 with iTunes 10.5 beta.

I upgraded to that firmware and i synced music very easily. Now,i needed to do a restore,and i restored from beta 5,but when i try to sync the music,it shows me "The iPhone cannot be synced. An unexpected error occurred (1150)". I googled, but i didn't find anything about this error. Who can help me? I tried to reopen iTunes too, and to sync my music,but when i press "Sync" button,2 seconds of time and it all synced,for iTunes. but in my iPhone there's stll not my music. Argh!