I also had this same problem the first day I picked up my 8700c. Talked with one of Cingular's chat techs...waste of time. Spoke with a tech the next morning at 1.800.331.0500 and explained my problem...showing GSM at times then EDGE. She said that I needed the free data package added back on to my account. It was an option that was removed when they switched my phones the night before. When she told me that she added it back on, it immediately went from GSM to EDGE and has been great since. I cannot remember the exact name she gave for the data package but it is free and runs a little slower than EDGE...GPRS I think. Hope this helps.

Shane