I've downloaded the RetroPie RPi2 v3 beta 4 image, flashed my micro SD card and set up controls for my Hori EX2 arcade stick. Every other emulator works great using the /opt/retropie/configs/all/retroarch.cfg input settings, but when I try to play a game using mame4all the controls are non responsive. I would assume this is using lr-mame4all emulator, but I'm not sure where to look to verify. I can't even use Start + Select to exit the games which all appear to be working fine otherwise. I have to remote login and killall -9 mame to regain control. I would be grateful for any tips to get this working properly.