Did you program the Uverse remote to control your dvd player?  When you changed your tvs input was the dvd player turned on.  Did you set your tv input to the input that the dvd player is connected to.  FYI, the DVD player should be connected directly to one of the inputs on your tv.  Either in the RF, composite, or S-VHS input.  There are several reasons why you aren't able to view your dvd player.