Originally Posted by Alan566
the 8th # on the ID: is 4
This means you have the current latest production 4033 sim card in your BB.
If this were a 2 or a 3 I would say to go to At&t and ask for a 4033 and see if it made any difference.
If you have changed out your sim card 3 times after At&t provided you a new sim, then I would suspect something with the hardware. Or, the current sim card they gave you is also defective even though they have replaced it so many times but unlikely since you have changed it 3 times.
To shed some light on this issue, this seems to happen with 8700c's (our corp standard) and 3033 cards as we get as many as 5 of these per day for setup. They will read "Sim Card Error" after sometime 4 minutes to 1/2 hr and this will sometimes clear but will continue to plague the user and phone. Pulling the battery does nothing and the symptom returns. I have also seen the 3033 act up on an 8310 curve and replaced with 4033 and "Sim Card Error" went away. When this "Sim Card Error" happens, customers loose email and are not connected to the network.
I have included a link to show how to identify the 3033 or 2033 cards. (Not a great photo - sorry) http://www.nettechonline.net/images/bb/sim/IMG00264.jpg
I would start suspecting hardware as there is either something wrong with the sim slot or the phone itself. I would try one more new sim and have them move your cell number over to the new sim and if it does it again, replace the phone.
Let us know how this plays out for you and good luck...