you are wrong something.. Gamepad0 is the first gamepad connected, Gamepad1 the second ecc.
NOT Gamepad1 the first, Gamepad2 the second.
see this
"Multiple gamepad devices can be connected to a single computer. To differentiate between them, most actions, conditions and expressions in the Gamepad object also take a Gamepad parameter. This is a zero-based index of the controller. For example, 0 identifies the first controller, 1 identifies the second, and so on..."