i know this is probably more of an O2 problem but i thought id ask here in case anybody knew anything. basically i replaced my damaged iphone with a brand new one today (which O2 sent out to me). the woman on the phone said i may keep the SIM card should i wish to keep my number. which i did. everything was fine. i registered the new iphone with itunes etc, nothing much was needed. and then i even texted a friend something, and he also replied to me. then all of a sudden this evening at work i noticed there was no signal - "no service" in the top left corner. and even when i got home it was still the same and hasn't changed since. anybody know what might be up?