Tried to update my Ubuntu host today and it did pickup that new version of VirtualBox is available (4.1.8). All other packages installed properly except that VirtualBox installation was complaining about missing dkms.conf file, see error message below.
Though it looks like installation was fine but I am concerned about its effects to VirtualBox functionality. To fix this, do:
Of course you have to replace 4.1.4 with the old version of VirtualBox that you don't need.
VirtualBox, Ubuntu, dkms.conf, file not found