I received a new AT&T router today to replace a faulty one that the iPad connected fine to. With the new one the iPad will only retain an IP address if I have the iPad set to DMZ. I tried all the encryption types, rest the router numerous times and cannot figure this out.

When I turn off the DMZ the iPAd will work for a few minutes then lose the connection and the only way to get it back on is to enable the DMZ again. I also tried the reset network option in the iPad. This is strange!