iphone 3gs stuck on waiting to activate screen

so my iphone was unlocked and jailbroken ack on 4.2.1. using baseband 6.15.00. so i decided to just restore it and start from fresh on 6.0.1. so i did the resored it and now it says waiting to activate and when i hook it up to itunes it doesnt seem to see the sim i have in it.. the sim is active on att network. i have tried rejailbreaking it and downgrading the baseband but the issue is i cant get into the iphone to see if the baseband changed or anything. please help!