Originally Posted by mendez777
Wirelessly posted (8100xxx8482;)
7280 device don't support 3G sim card....you have to put it on bold or storm...
This is not correct. Please check your facts before posting.
The real problem is that the device is from the original AT&T Wireless, and the SIM card you have is from the new at&t Mobility, previously known as Cingular Wireless. AT&T Wireless phones cannot accept Cingular or at&t SIM cards. As such, you will need to get the device unlocked to use a SIM card from the current at&t.