No Signal Bars, Iphone 3G, Jailbroken

[khangul]

I researched a lot, but can't find an answer.

First of all, I used to have a 2g iphone. I sold it and just bought a 3G off craigslist. Now I don't want to get an iphone plan (Data plan) from AT&T.

I realized that the 3g iphone was updated to 2.2.1 and the bootloader now is 5.9

I just jailbroke the phone using quickpwn225. I only have one bar, can't make any calls. I can't even import my sim contacts.

Now is this because the phone is not unlocked?? But I have an AT&T sim, so it should work??!!!!!!??
At the moment the phone is on 2.2.1 jailbroken!!

Please help if there is a way to fix this, AGAIN I don't wanna get iphone plan from AT&T.
Life without an iphone is hard/boring/empty..lol..

any help guys???