We are having the same exact issues (and then some) down I-71 here in Cincinnati.  From personal experience, and from what I'm hearing from my friends and different online posts is that the problem is pretty much widespread with AT&T and their overloaded network.  Not only that, but the 3G service in Cincinnati is still bad after they allegedly upgraded and tweaked the network back in November of last year.  I drop at least 40% of all of my calls, the 3G data is really slow and sometimes won't even connect, the call/voice quality is really bad where you hear crackling and interference in the line, my voice mails won't come through, only some texts will come through, I get network busy/connection error messages a lot, etc. I could go on.  After numerous calls and trouble tickets were opened, nothing is ever fixed.  I will be switching to Verizon the day my contract is up.