I did something really stupid. Hindsight is 20/20.
Had a nice shiny 8GB IPhone with 1.1.4, jailbroken and activated with Ziphone 3.0. Life was good.
Long story why, but I installed 2.0 build 5a258f, then had to remove it. I restored 1.1.4 via Itunes, then once again jailbroke and activated via Ziphone. All worked fine - but no signal. My SIM is in, the phone sees the SIM, but no carrier name and no bars.
Tried restoring again, this time jailbroke and activated using iLiberty+, same deal.
One weird thing - I can't get the Baseband to change at all - it's stuck at 04.05.02_G. I tried the iClarify baseband eraser, but I think it's hard coded to remove 04.05.01_G? All of the "I'm a retard and accidentally installed 2.0" threads are for previous 2.0 releases with a different baseband.
I just can't find a way to re-virginize this, or just to get it to make calls in any other way. Does anyone have any ideas? If someone can help me figure this out I will owe them a beer. Thanks so much for any help that you give.