I have Ubuntu 12.04 running in a Virtual Box virtual machine, on my Windows 7 32bit system. It has been working great, except that the backtick/tilde button sticks(not physically).

When I hit the backtick button it keeps repeating until another input button is pressed. So if I press the spacebar while the backtick is repeating, it stops, but if I press the shift while it is repeating, the backtick turns into a tilde, and the tilde keeps repeating until I release the shift key (at which point it's a backtick again and keeps repeating).

This sticking behavior only happens with the backtick key, and only in my Ubuntu virtualization, never in windows.

I've tried both my laptop's keyboard and an external USB keyboard and the problem happens on both. Both keyboards I've tried are Japanese 106/109 key layout, but I'm using them with a English(US) 101 profile. When I refer to the backtick key above, I mean where it is on the US layout.

If I use the Japanese profile, the key in that location (the US backtick location) still sticks, but its no longer mapped as the backtick key.

Any thoughts as to what might be causing this and possible solutions?

I've searched a lot, but have not found any help so far. Any help is greatly appreciated.