Looks like a button is active when it shouldn't be.. I'll take a look.
EDIT: Found regression. It appears to be something awry in the conversion to the actual Namco 5XXX devices.
EDIT 2: I found the problem. It actually affects Grobda, Motos and Phozon whereas the second player in cocktail mode did not have directional control. I sent in a fix and it should be fine for 0.141u2. http://www.mametesters.org/view.php?id=4214