Left Ctrl key not working in VirtualBox

While running an OS in VirtualBox on Ubuntu 10.10 amd64, I find the LCtrl(left-ctrl) key is not being properly detected. (The RCtrl(right-ctrl) is used by Virtual Box, but the LCtrl key should be available.) This makes programs like Emacs, that heavily rely on the control key, not work correctly. Searching the Internet, I found similar complaints that were fixed in by turning off Show position of pointer when the Ctrl key is pressed" in mouse preferences. Since this is already turned off on my system (actually in both host and client OS's), I don't think this is the problem.

My question: is this a bug, a feature or operator error?

As a workaround for Emacs in Virtual Box you can operate the control key functions by pressing

CapsLock+Control then release CapsLock while holding Control and press the corresponding funktion key (e.g. N).

To make use of the right shift key (however that key is also not fully operational in Virtual Box) you can define another Host key from the Virtual Box Manager settings in File -> Preferences -> Input.

In Ubuntu 12.04, disabling the mouse pointer (System settings ► Mouse and Touchpad ► Show position of pointer when the Ctrl key is pressed) does the trick.

I could get the control key to work by disabling "Highlight the pointer when you press Ctrl in the mouse preferences. This was on Fedora with Gnome 3, so it might not help you.