When I have VirtualBox fullscreen hitting KDE shortcut keys don't work (as they probability should not) because "I'm trying to act with my virtual machine" and don't want to be disturbed. Not even KDE's killer ctrl + alt + esc works. But, I have yakuake installed and that works. For those of you who don't know, its a konsole which basically drops from the top of your screen (similar to the one from quake and other games). To make it drop you press f12. However, when I'm in VirtualBox full screen, pressing f12 makes yakuake open.

Somehow, yakuake is able to recieve these events, but regular kde is not. The reason I'm asking is that I would actually like some of KDE's shortcut keys to work, regardless if VirtualBox is fullscreen or not. Really, (and this is sorta a silly reason) I would like KDE's ctrl + f11 shortcut to bring up the desktop cube. I think it would look rather cool to have 4 different Operating Systems running on different faces of the cube (all in full screen).

Does anyone know how to tell KDE to allow shortcut keys to work even if VirtualBox is full screen. (Or just know how to enable 3d cube in the middle of fullscreen stuff, such as games, or VirtualBox).

I had the same problem. I have only Kerry Beagle search shurtcuts acting in VirtualBox fullscreen mode.

I (and my friends) used the next solution: press (and release) your HOST key (by default in VirtualBox it is right-control) and press shortcut after. As for me, I prefer to use Menu key as HOST key for VirtualBox.

The HOST key disables VirtualBox keyboard capture, so you can use KDE shortcuts. Press HOST once again to return VirtualBox keyboard capture mode.