Sometimes some of my UI's disappear, but the processes they belong to lives on. So far it has happened to gnome-terminal, emacs, eclipse and evince. I've only experienced this behavior with the Awesome Window Manager. Any ideas how to fix it?
Update: It has also happened to a popped out Gmail chat window . When I close the main Gmail window, it warns me that the invisible chat window will also be closed.
Update 2: I should mention that I'm using Awesome with Debian inside Sun's VM Virtualbox, and the error seems to occur more frequently when the VM leaves/enters fullscreen mode.