"you must sync with your computer before you can use ipod"

[JoeyAmaranto]

hi all

ive got an iphone 3gs and just updated the brand new software.... ive gone to open my music to listen to and i get the error message "you must sync your computer before you can use ipod".... so ive done this, and the same thing happens.... ive synced it over and over to no avail... ive also checked my itunes to see if there is any music on my iphone and yes, its showing 20gig worth of music so it's definatly in there.... i dont know what else to do... any ideas???

thanks in advance, Joey