How do I record fullscreen programs using recordmydesktop?

How do I record fullscreen programs using recordmydesktop?

I am trying to record a game in fullscreen using recordmydesktop but once
the video finishes being processed, the resulting video shows my desktop
instead of whatever I was recording.
I have enabled full shots at every frame, as other sources have said that
may be the problem, but the problem still persists.
EDIT: Problem only exists for 3D windows, like said game.