Comment 1 for bug 315819

Hello Alan.

Actually, if I am not mistaken, the key combo itself is for restarting X, not killing it. That would also explain why it works on all of my machines. I would assume there is some flaw in your xorg.conf or (which is more likely) the graphics driver, preventing X from restarting properly.
I am moving this bug to the xorg package for further investigation.

Thank you for this report, and have a nice day :)