I have a Philips SRM 5100 remote, which is a 'Green Button' MCE remote. It has native Windows MC support but JRiver does not detect it.
It's why I think I can't press and hold directional keys (left, right, up, down) to quick scroll through Theater View - I have to single press so do this through a 500+ film library to get to the end one.
Also don't seem to respond to alpha key presses to jump to the first film matching the key presses.