User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1) Gecko/20061204 BonEcho/2.0
When a window is in full screen mode.
you press Alt + F5,
and then, Leave Full screen mode using Alt + F11.
Now, you press Alt + F5 again.
It will behave like Alt + F11.
Steps to Reproduce:
1. make a window be in full screen mode. (Alt + F11)
2. Press Alt + F5 to leave the full screen mode.
3. Leave the full screen mode again. (Alt + F11)
when you maximum the button, You'll get the wired behaviour.
In full screen mode,
Pressing Alt + F5 shouldn't change the state of the "Window"
Actually, the window is not switched back to fullscrene, it's simply restored to the fullscreen position/size. If you move it (using Alt+click), you'll see that it's still decorated.
BTW, it should be fixed with rev. 24105, by preventing fullscreen windows from being maximized.