New AT&T Blackberry 7290 and My Existing Cingular SIM...
 

Hi. Hoping someone can help here. I just got a new Blackberry 7290, AT&T branded, but when I put in my existing Cingular SIM card in there, I get a data connection refused error although the phone works fine. Calling Cingular/AT&T for help, they tell me that the AT&T and Cingular data networks are not compatible and that there's no way for me to use my Cingular SIM on my AT&T Blackberry. Is this true? I'm thinking there's some setup things that's required for my existing Cingular account for me to access the Blackberry network, no? Please help. Thank you.

When they say that Cingular an AT&T's data networks are not compatible, they may be referring to AT&T using 850MHz and Cingular using 1900MHz, but the 7290 is a quad-band phone that supports all GSM/GPRS frequencies. I suspect that the problem may be that you do not have Cingular's BlackBerry data service, which is different from their "regular" data service.

I got the same error when putting a SIM from an AT&T UMTS card into an AT&T GSM Blackberry

Is anyone actually using a AT&T branded 7290 on the Cingular network?

I'm using an AT&T branded BB, with an AT&T branded SIM chip. It displays Cingular on the main screen sometimes, but mainly AT&T Wireless appears in the ribbon on the main screen. Hope that helps in some way. :)

Acutally was interested in whether a Cingular SIM (with Blackberry data access) works on a AT&T unit. I'm thinking it doesn't based on some other things I've read regarding different network settings between AT&T and Cingular. The AT&T unit is preconfigured with AT&T configuration so either I would have to figure out all the Cingular equivalents or try and get help from Cingular support (which I've heard is not very good).

Well, there's an easy way to find out. Add the service and test it. If it doesn't work, cancel the service.