Iphone starts to drop calls, And doesnt even show up calls.

[fcampisii]

Hey guys, I have had my my iphone 2g, since april and everythign has been running fine, but about 3 weeks ago it has been droping my calls,now while i am talking to people but sometimes when they call my fone will just hang up on them, or when they call it will ring for then and keep ringing but i will not get the call. And it starting to happen very frequently. I have been searchign around the forums ad havent seen anyone with similar problems, But hopefully somebody can tll me what the probem could be or how i could this. And i have already tried to do a clean format on the phone and take out the simcard and put it back. Any comments will help out, thanks.

[reeko]

i have been having this on my 3g aswell