WTF?
When I'm on 3G @ work my signal is -89
i can see why it would go to Edge if it can no longer cling on to 3G..but GSM? I noticed I get dont get SMS or Emails on GSM
AT&T reception has been complete garbage for the last few weeks... It's cycling all over the place in places I used to get good reception... Wonder what they're doing.
From here, choose any other Networks. (Other than the one you are currently using). I recommend choosing a Network which you think has the best signal/coverage. Choose other network for a while (you will get SOS). Leave it for a few seconds. After that, choose your Network again.