I have an original iPhone (2G) on a family plan with my wife's dumbphone; we never use anywhere near our allowed minutes, and have something over 6000 rollover minutes right now. Since AT&T will no longer allow you to drop the data plan (since the 3G was released), and I don't really need iPhone service, I decided to get a cheap Nokia and trade the SIM card into it. Everything worked fine when I did (as expected), and when I checked my account on AT&T they immediately sensed that I had changed phones and showed a Nokia 6102i as the active phone on my line instead of the iPhone (again no surprise). However I did get a surprise when I checked my account today and all calls made since I switched have been charged as overage! Once I noticed this I changed the SIM back to my iPhone and checked the account; it properly showed the iPhone instead of the Nokia; it still shows the minutes of overage on the account (all from the Nokia) and shows all other minutes at 0 (my billing cycle just started again on 4/15). Does anybody know why this happened? I think after this that I will just keep my iPhone w/data until my contract ends in September and then port my number out to T-Mobile.