QDX 6000 doesn't respond to remote control

I'm trying to call using a QDX 6000 but the system doesn't seem to respond to the remote control. The main unit seems to register that the remote is being pressed because the light changes color when I press a button on the remote, but nothing changes on the screen.
Is there another way to change what is on screen(keyboards, mouses, etc.) or is there a way to make the system work correctly?