Description of problem:
According to the default setting in the Keyboard section of control-center, the key combination Ctrl-Alt-Del should log the user off.  Instead, that key combination brings up a Power Off window (with options: Cancel Restart Power Off).

Version-Release number of selected component (if applicable):
$ rpm -q control-center
control-center-3.4.1-1.fc17.x86_64

How reproducible:
Every time the Ctrl-Alt-Del key combination is pressed.

Steps to Reproduce:
1. Log on to the Gnome desktop manager.
2. Press the key combination Ctrl-Alt-Del.
  
Actual results:
Instead of logging off the user, a window prompting the user to Cancel/Restart/Power Off is displayed.

Expected results:
The user should be logged off or prompted with a window asking them whether they want to log off.

Additional info:
I used the Keyboard application and selected Shortcuts to change the keyboard shortcuts under the System settings.  I changed the shortcut for "Log out" to Ctrl-Alt-o, in case Ctrl-Alt-Del was a special case.  This new key combination had the same result, that is, it still prompted the user to select a Power Off option instead of a Log Off option.