Safari Bug on Lion: The application Safari canceled restart

Noticed a bug on my Safari after upgrading to Lion. Haven’t been able to recreate it is as it appears to be random, when using Safari and you close some tabs. When you try to quit the Safari, the option is greyed out from the Safari Menu and Command+Q does not work. If you try to restart your mac you’ll get the screen shot below.
Read more about Safari Bug on Lion: The application Safari canceled restart