New G1 user problem with ATT go sim card

[Bracedagr8]

Just got my G1 unlocked. i tryed to unlock it with att go phone sim and would not...then i put in my work att sim 9says cingular on it) and it worked fine to unlock and to call and text...then replaced with att go phone sim and it doesnt work...can someone please help... thanks

[Reallyneatgirl]

If your att sim is reasonably new, it may be locked to its original phone. Some of the sims will lock to the phone it was originally registered to for 6 months.