ok i just bought an mxp 200 unlocked and i have cingular ilike it in all but i have problems making and recieving phone calls it sayd i have full sig but nothing it always gives me and error about network coverage or somthign is there any this i ca do to solve this so that i may make and recieve calls in piece. ( i have no signal probs when i use ym cingualr phoen just this one)