I have an unlocked Nokia C3 and have had some problems setting it up correctly with the AT&T network.
When the phone is unused, the "E" Edge status icon is on the screen, but if I make a phone call, a line goes through the "E". Does this mean that the Edge is not working correctly with the settings I have on it?
I drew a picture of what it looks like during a phonecall.
I presume you have the C3-00 with the QWERTY keyboard? (Not the C3-01 with just a numeric keypad. lol. I hate Nokia's naming scheme these days. )
If I'm correct, then I believe your phone is simply indicating you don't have access to the data network while you are on a phone call. GPRS/Edge are data only services - not voice; and the C3-00 is not a 3G phone, so there is no simultaneous use of voice and data with it. When the "E" is not lined through, it is indicating that data service is available and ready for use.
=^..^= There must be a happy medium somewhere between being totally informed and blissfully unaware.