I can't Command+Q out of Safari

Recently I have been unable to use the Command+Q quit option for Safari. When I go into the menu the Quit Safari option is grayed out. The only way I have been able to quit Safari is by right-clicking it in the Dock and chosing quit, or force quiting it. The Safari Version I am using is 5.1.7 and the OS X is 10.6.8. Any help would be appreciated.