Default Network issues

I am not really sure what happened. I have JF1.51 installed on my g1 and haven't had any issues at all with it. Today for some reason my phone stopped recognizing the t-mobile network. I tried multiple sim cards and haven't had any luck. My wife has a completely stock g1 and her phone works fine even with my sim card in it. I have tried going into call settings and it just says network error. I know that the phone is still under warranty, but I can't downgrade back to rc29 because I won't be able to re download the updates since I can't log into my gmail account. Does anyone have any ideas on what I should do? I really can't afford a new phone. I could just install one of the roms that doesn't have any theme modifications, but not sure if they would noticed I have an updated spl and radio and apps2sd. Please give me some ideas. Any help is greatly appreciated.