FYI, I recently added Ubuntu 12.10 as dual boot with Mint Cinammon on my notebook and found that Virtualbox would not work. Some posts suggested the following code for the terminal
sudo apt-get install dkms build-essential linux-headers-generic
sudo /etc/init.d/vboxdrv setup
Apparently this worked for some people but it did not work for me! If this happens to you, I found that adding the following lines in a terminal finally got Virtualbox to go
sudo apt-get install linux-headers-3.5.0-17-generic
sudo /etc/init.d/vboxdrv setup
Good luck!
sudo apt-get install dkms build-essential linux-headers-generic
sudo /etc/init.d/vboxdrv setup
Apparently this worked for some people but it did not work for me! If this happens to you, I found that adding the following lines in a terminal finally got Virtualbox to go
sudo apt-get install linux-headers-3.5.0-17-generic
sudo /etc/init.d/vboxdrv setup
Good luck!