Why won't any dance pad work on my PS2?

I just bought the PS2 because I realized I'm addicted to Dance Dance Revolution. I purchased a Pelican Universal dance pad, and it didn't work with the system. But the PS2 controller works. I took it back and was forced to buy a Disney edition of DDR just to get the Konami dance pad. However, that too does not work. I can step on the "Select" and "Start" parts of the mat and those will work. But no arrows work with the game, so I end up getting BOO all the time. This stinks. Anybody have any suggestions? thanks a lot.