Go sim in iphone?

[nktrnl]

I tried to search but could not find the answer.
I started off with this question Used 3gs help, please
So I got blackra1n and am now jailbroken. I have a fresh at&t go sim, should the phone (3gs) work? or do I need to be unlocked to use that too? Im getting no service. The card is activated, and works in the go phone that I got with it, just not in my iphone.

Do I need to do a restore to attempt to get signal again? If I do this will I have to activate the phone again? If I do have to activate again can I do it with the go sim?
Thanks in advanced.

[nktrnl]

Well incase anyone else is wondering about a similar question, here it us:

I threw the sim in my 2G (unlocked/jailbroken) and got no signal/service. so thats part one. Dont use a go phone sim. Part 2: with a restore, yes now I need to try and activate the phone again...hope this helps some one.