Talked to a friend of mine. They don't want to admit it, but it's capacity issues.
Let me expand with nerd talk to make your head spin.
Basically all of the AT&T towers in the area are not exclusive, most phone companies aren't anymore. Each tower generally goes to a T-1 fiber optic line, but that's not always the case especially in "rural" areas like ours. In some cases they are connected by a standard copper wire and in some extreme cases they are daisy chained via short run satellite.
At any rate this all winds up at a "switch" in Pensacola. Basically this is where all of the phone lines for the 850, 334, and 251 area codes end up. This switch controls every call, text message, and voice mail. It was upgraded back in 2001 in anticipation for (hole on you'll love this) all the development that was to come. It hasn't been upgraded since and is currently over loaded. Apparently someone thought it would be a great idea to have one switch that runs all of the phones (local and roaming) from St. Marks to the Mississippi/Alabama state line.
Basically you're pucked until they upgrade or the tourists leave. Guess which one's going to happen first?
P.S. This switch affects all of the phones in the area and is ironically owned and operated by AT&T.
P.P.S. I was also told that we have a huge shortage of bandwidth in this area and this could be affecting phones as well. That one I'm not really sure about though.