I'm using VirtualBox on Ubuntu 9.10 with Windows XP as the guest OS. It's pretty annoying that when I in guest OS - I can't switch virtual desktops(workspaces) on the host(Ubuntu) by pressing ctrl+alt+(Left|Right|Up|Down) because of Virtual box captures these key combinations. Is it possible to disable keyboard capture for some key combinations ?
This question is old, but I found a better solution that probably didn't exist back then.
You can disable "Auto capture keyboard" in Manager window -> File menu -> Preferences -> Input:
This disables the automatic keyboard grabbing completely, so window manager keybindings are passed directly to it.
In this mode, the 'host' key has the opposite effect - it enables grabbing instead of disabling it.
While there are some Host Key shortcuts that activate certain VirtualBox functions (eg, Host Key+P which pauses the Guest), I don't know of any way to configure VirtualBox to send Host Key shortcuts to the Host OS.
In the meantime, you can use the Host Key to release the keyboard from the VirtualBox Guest's control. By default the Host Key is set to Right Ctrl. You can see the current Host Key in the VM window:
Just press the Host Key once to release the keyboard capture. After that, your Host OS will see your keypresses. So here's your workflow: