So are you saying that you aren't wireless now? Or you removed the wireless router and are now using a wireless modem instead?
AT&T can test the signal to your DSL modem without ever going to your house. If that checks out, and I'm guessing it did, I would not think crazy wiring is the...
The first thing that comes to mind is "wireless". I've only found wired connections to be very reliable. With a wireless router, the further away your computer is from the router, the worse your signal. On top of that, most routers transmit at 2.4 GHz. Many other consumer products operate at...