unlocked tmobile 8900 with att prepaid simcard

[Itzjusnick]

Hi i recently purchased an unlocked t-mobile blackberry curve 8900. i put my prepaid att sim card in and it is give me an invalid sim error. if i use a non prepaid att sim card it works i dont understand whats going on?

[Deathcommand]

Is the SIM broken?

Posted from my CrackBerry at wapforums.crackberry.com

[Itzjusnick]

Its not. it actually works in another phone when i put it in that phone. but its a cheap att flip phone haha