I've read numerous threads about this same issue with earlier versions of Ubuntu but unfortunately the solution presented in every thread I've read hasn't worked. Most of these threads point to the "Hide all normal windows and set focus to the desktop" keyboard shortcut as the culprit. When I set my corresponding "Hide all normal windows" keyboard shortcut to 'disabled' nothing changes. Per another thread (http://ubuntuforums.org/showthread.php?t=1595871) I also tried to find some shortcuts via gconf-editor but the /apps/metacity directory does not contain a 'global_keybindings' entry, nor does my '
/var/lib/gconf/debian.defaults/%gconf-tree.xml' file contain a 'show_desktop' entry. If anyone know the cause of this issue or has any suggestions on where to find other keyboard shortcuts setting locations related Ubuntu 12.1 or xrdp I'd greatly appreciate it.