I recently installed Linux Mint 14 (upgrading from 12, clean install) and have gotten everything back to normal except my keyboard shortcut. I remember having to do something special to get Mint to recognize the "Menu" key (that normally opens context menus) to function as a valid key for a keyboard shortcut.
Menu -> Preferences -> Keyboard -> [Keyboard Shortcuts] -> [Custom Shortcuts] shows "Launch Terminal" bound to "Menu", but pressing the Menu key does not invoke a terminal.
Restarting did not fix the issue.
Menu -> Preferences -> Keyboard Layout -> [Layouts] -> [Options] -> [Alt/Win Key Behavior] is set to "Hyper is mapped to Win-keys" : still no dice.
I can't remember what I did to get it to work last time, and 30 minutes of Googling only turned up the above 3 solutions - none of which worked.