Incorrect SIM error: I think I broke my iPhone

Hi, I read a lot of sites and I was very carefully downgrading my firmware to install jailbreak so I could install a stealthsim to get my iPhone working on TMobile and either (1) 1.1.3 was on my phone and I didn't realize it, (2) I installed 1.1.3 by accident along the way in some sort of classic noob move (it took me a bit to get a hang of what I was doing), or (3) some other hell broke loose. In any event, I now am stuck with the 1.1.3 firmware and a bit fat error telling me that I have an incorrect sim. I can't plug into iTunes, because iTunes is puking because of the incorrect sim error.

I have tried downgrading to 1.1.2, 1.1.1, and 1.0.2. I am willing to try to downgrade lower if I think it will help. Does anyone have any ideas? I am comfortable with a command line and I don't need a walkthrough -- just a website that can point me in the right direction, but my GoogleFu is failing me on this one.

Please don't tell me I'm fated to wait until the SDK comes out on Feb 29. I can't use my crappy Moto V3 that much longer!!!!

Thanks.