Well, I don't know if this will help, but I brought it back down to basics and it still doesn't work.
(I hope I attached those pics right!)
I went back to the standard Mala layout (no tree structure,) turned off layout specific sounds, and added just ONE wav to it, under "Game list/menu movement." Using my full mame list, NO sound triggers when scrolling in the game list, but when the menu is up (last pic) the .wav triggers every time I scroll.
I'm really confused.

This isn't a problem for anyone else?
EDIT: Egad... sorry about those file sizes...
