Well i got this 6680 for 7 months. never had problems before. but not when I try to make call I receive this error: CONNECTION ERROR. I have full signal so that's not the problem. anyone have any ideea why? this happend only when I try to call. My friends are telling me that phone is close when they try to call and I think is because of this CONNECTION ERROR as I never close the phone.

First, ask network if is something about network. Could be...

full flash ur handset........all fine.......luck.....dude