Itunes 10 won't sync music

[kuato]

I have a jailbroken Iphone 3G running 3.1.3 and after I installed Itunes 10 it hasn't synced my music. I check the manually manage music and videos box and then apply. After I set it to sync with my music, the phone backups, syncs apps and contacts, then finishes. It never even attempts to sync my music. After this I check back at the summary tab and manually manage music and videos is unchecked now.

I never had any problems until I updated to Itunes 10, but I have installed some thing via cydia but nothing that I know of which would interfere with music syncing.

Any suggestions? Thanks!