user can't quit black-box game in Gnome Classic desktop session

[rpr nospam]

How to reproduce:
(1) Log in as a guest using a Classic Gnome Shell session (select Gnome Classic in the login window), which starts the desktop session as:
gnome-session --session=gnome-fallback
(2) Set the screen resolution to 1024x768 or higher.
(3) Start the black-box game, which runs in full screen mode by default.
(4) Clicking "Quit" does not quit the game but shows the help instead. It seems there is no way to quit the game and get in control of the desktop from current desktop sesion. (I tried various keyboard shortcuts, e.g. Alt+F1, Alt+F2, Ctrl+Alt+Delete, Ctrl+C.)
(5) Switch to the textual console with Ctrl+Alt+F1, log in and kill the black-box process:
sudo pkill -9 black-box

A workaround is to start the black-box game in windowed mode:
black-box -f &

The problem does not exist when the game runs in a Unity session.

This was tested on Ubuntu 12.04 64-bit and 32-bit with gnome-shell 3.4.1.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: black-box 1.4.8-2
ProcVersionSignature: Ubuntu 3.2.0-29.46-generic 3.2.24
Uname: Linux 3.2.0-29-generic x86_64
ApportVersion: 2.0.1-0ubuntu12
Architecture: amd64
Date: Tue Aug 7 00:03:00 2012
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
SourcePackage: black-box
UpgradeStatus: Upgraded to precise on 2012-05-19 (79 days ago)