I switched to virtualbox-3.2 3.2.6-63112~Ubuntu~lucid a while ago to see if that solved the problem, but I had the same problem with the non-free version as the OSE version until I upgraded the libqt4 stuff. Currently running libqt4-core version: 4:4.7.0~beta2-0ubuntu1. With that, it works.
I switched to virtualbox-3.2 3.2.6-63112~ Ubuntu~ lucid a while ago to see if that solved the problem, but I had the same problem with the non-free version as the OSE version until I upgraded the libqt4 stuff. Currently running libqt4-core version: 4:4.7.0~ beta2-0ubuntu1. With that, it works.