New iPhone 4 won't complete sync?

Just bought an iPhone 4 off someone and he assured me it was all fine.
Get home, connected my sim card and everything was backed up from my previous phone and went on smoothly.
Its 32 gb and I have plently of room. When I got to sync it, it goes from 'preparing to sync' to 'syncing mail accounts' and then step 3 of 6 is 'determining what apps to sync' and from there the synv just stops and I'm not sure what's wrong. The iPhone is updated.

Geekworldtech.com has a great iOS section on their forum. Go check it out and I'm sure they will have an answer for you in no time at all!