[ubuntu] microsoft keyboard's logout key doesn't work

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http://ubuntuforums.org – I have a Microsoft wireless multimedia keyboard and when i try to assign the logout command to the logout key i have in my keyboard, the key won't get detected as an accelerator. Can someone help me out? The sleep key next to logout works fine. I also tested this on windows and the key works, so its obviously not faulty (hardware-wise) Im using Ubuntu 12.04.1 LTS with gnome 3.4 (Hardware)