iPod iPod won't sync with new iMac

[nealeholl]

I just bought a new imac, and migrated all my data over to it from my old imac. I then bought some music on itunes. When I plugged in my ipod classic, it said the usual stuff about it not being registered with this computer. I said "Yes - register" etc. etc. and then got a message that I had now successfully registered my ipod with two of the possible 5 computers. However it didn't seem to sync with itunes, (despite showing in the itunes left-hand panel). When I tried to force it to sync, it went back to telling me it wasn't registered. This happened repeatedly until I got bored trying. Any ideas??