[SOLVED] What key sequences kill an app in Xorg?

[movEAX_444]

I am using Xmame running in Xorg on an arcade (MAME) cabinet. A certain combination of keys kills Xmame with this error "X connection to 0:0.0 broken (explicit kill or server shutdown)."

The keys that are being mashed are:
Left Control
Left Alt
Space
Left Shift
and
Z X R F D G A S Q W I K

The only one I know of is ctrl+alt+backspace which ends Xorg itself. I am loading Xmame through SSH and I get the above error in Putty, while Xmame dies and I'm returned to my window manager.

[hard candy]

Ctrl+C kills apps in consoles, have you tried it in Xorg?

[movEAX_444]

I know but C isn't being used, so how is ctrl+C being used?

[movEAX_444]

Ctrl+Alt+K kills whatever is open. It was in the Fluxbox config I was using. I thought Xmame took all the keys when it had focus, I guess not. It's sorted out now.