Long subject line, but I think it does a good job explaining it.
Certain keys (up arrow, enter, a few other random ones) aren't recognized inside MAME. If I'm at a bash prompt, I can hit up for the previous command, use it to scroll in Firefox, etc. But as soon as I fire up MAME, it's like the button doesn't even exist. Down, escape, left, right, tab, and most others work, but there's a subset of seemingly random buttons that just aren't recognized.
Any clues?