I have an Issue with Ubuntu 13.10 x64. Fairly recent install since I dropped back from the 14.04 beta.
The issue is both the Restart and Shutdown menu items (from the upper right menu), when clicked show the 'do you wish to log out' option; this leaves me with either 'Lock' or 'Logout'.
sudo shutdown 0 sort of works in that it gets me out of X, but then simply drops me to a root prompt and doesnt turn the computer off.
The Suspend button still works correctly. When I click the Logout or Lock option at the prompt, nothing happens and the prompt simply disappears.
Processor: Intel Core i7 930 @ 2.80GHz x8
Graphics: AMD Radeon HD 6870 (using 14.3 Beta 1.0 drivers)