format to a mac? ipod problem

So i just purchased a cheap 3rd Gen (the guy said it wouldnt connect to his PC and was finicky) and have had a couple problems. First my mac wont really know the ipod is connected even though its charging through the Firewire on my imac G5. I have occasionally gotten some songs on there when it does decide to find it and when I play songs, sometimes it plays them, sometimes it skips 3 songs ahead (syncing problem?). So i have tried to restore when it will read it and i have no idea if it works or not, and I think with older ipods you have to switch to a mac? to be honest i have no idea. Like today it was working fine with the itrip, so basically just need some suggestions, maybe what order to do things (ie restore, update, use a cd? delete itunes and start over again? use disk utility?) I know this doesnt make any sense what so ever, but any help would be good. Thanks guys/gals

I used to have a lot of problems with my 3rd gen ipod but since I restored it its run much better and I haven't had a single problem.
Use the ipod updater and hit restore (Warning: This will erase everything on your ipod).