Help! After jailbreak iPod Touch 2G by Blackra!n all my proviouse applications dead?

Hey guys, I need your help. Yesterday I just bought and tried to jailbreak my new iPod touch 2g 3.1.1. First I upgrade it to 3.1.2 and jailbreak by using Blackra1n. Everything looks fine. When I reboot it and try to use my previous applications (such as, Facebook, Fling! …) but all dead can’t use anymore.
What’s wrong with that? Anybody can help please!!!!! P.S: I tried to restore it twice but still no luck!