Comment 5 for bug 536929

I can confirm on virtualbox OSE in Karmic, running a Lucid guest. This advice [1] fixes the problem. You have to install guest-additions, then *before* you reboot, edit /usr/src/vboxvideo-3.1.4/vboxvideo_drm.c and then run sudo /etc/init.d/vboxadd setup.

[1] http://maxolasersquad.blogspot.com/2010/03/ubuntu-1004-lucid-lynx-alpha-in.html