Need to unlock iPhone 3G running 3.1

[Walterrific]

I have an iPhone 3G that got the Apple iPhone 3.1 update. I used PwnageTool 3.1 to jailbreak it, and Cydia to unlock it... but, when I put my SIM card in it still doesn't work. It just says "Searching..." where "T-Mobile" should be. This phone has 5.11.07 firmware. Do I have to downgrade it? If so, how?

I would appreciate any help, thanks.

 

[Tramain]

Please Search there are many threads on this. http://forum.theiphoneblog.com/ipho...otloader-5-09-help-downgrade-if-possible.html