recently I found a terrible problem of my android. after start the phone 1 day, I found I can not dial a call even I have full signal, and if I try to call my android phone from other phone, my android don't have any ring or prompt.That means if someone call me, then I won't know, and the phone will have no log about the call!!!! and after I found this problem I restart my HTC magic, and then everything is OK again, but later if will happen again. I don't what problem cause this thing happen, is there any method I can find out the reason of this issue ? How can HTC magic be so unstable ????