help :D 6.1.2 no service error (jailbreak related)

i updated my 04.26.08 baseband iphone from some very old 3.x jailbroken version to 6.1.2 using sn0wbreeze (i have cydia and i made sure to hacktivate it) But the weird part is when I plug in my tmobile sim I am stuck on NO SERVICE now. Wut do?

by the way when i connect my iphone to my computer and run redsnow it says I am on 6.1.2 with 04.26.08 for my baseband.