iPhone doesn't accept songs from iTunes ???

hi guys

i tried hooking my buddies iPhone [set up on a Mac] to my Mac and give him a playlist or 2.

everything was seemingly ok -- i even updated his software -- the iPod showed in my Devices and i was pretty sure we were good to go...

1st - i switched to "manually manage music" then...

however - when i looked at the music on his iphone -- it was all grayed out.

and when i tried to drag my music onto his library -- nothing happens!
it just wont let me add any music at all!

any ideas??

thanks in advance