I have a Blackberry 8700c. I got it from my company I work for. They pay the bill. I've had the phone since before AT&T bought out Cingular. So the sim card is still a Cingular sim card. Does anybody know why when I put the sim card in another AT&T or Cingular phone, I can only make calls? I can't use the internet unless the sim card is in a Blackberry. I've put my sim card in my girlfriend's Blackberry Bold and it worked fine. I've tried it in a Samsung Blackjack and can only make calls. Any ideas?

Someone mentioned to me that my card may have a lock on it because it is outdated. Possible?

From what I understand, my sim card, which is a 32k Cingular sim card is outdated.

How do I go about getting a new 64k AT&T sim card?

Wirelessly posted (Tmo's cheapest BB customer)

Maybe because BlackBerry data plans only work with BlackBerrys?

Wirelessly posted

That still doesn't make sense. My girlfriend has an unlimited data plan for her Bold. Recently, her Bold broke so she used her old Blackjack, which is now my Blackjack. Everything worked fine.
I believe I figured out the problem. I have an old 32k Cingular sim card. I need an AT&T sim card, I believe its a 64k 3G sim card.

Wirelessly posted (Bold 9000, answers to HAL)

I recently got a new SIM card because of some data problems, now my battery lasts all day with wifi on. Used to have to plug in around noon.

Back when I was on AT&T, I used to swap the SIM card out of my Bold and into a bunch of different Nokias, just for a change of pace sometimes. I never had a problem with data as the unlimited BIS seemed to incorporate a regular full AT&T data plan.

The exception is with iPhones. They require a specific iPhone data plan, much like BlackBerrys require their own data plans, and the BB plan is not iPhone-compatible, and vice-versa.