Originally Posted by mrrangerman
Yes sound like the F11 key to me also.
If the F11 key is pressed it will cover all the tool bars making it almost impossible to anything else.
I should have been more lucid in my explanation. What I meant was that, at least on all the systems I've used Firefox on (Windows and Linux), when you're in the F11 / Full Screen mode, when you take the cursor to the upper edge of the screen, Firefox's own toolbar "unhides" itself, and that give you access to the minimize / restore / quit buttons. But, of course, that wouldn't work if you were running the window manager with no "window decorations".
Having all of these choices can be wonderful, but it can also make things pretty complicated guys (like me) who are new to the environment.