Thanks Brian,


dpkg --configure --pending

Will try to automatically configure all pending packages.

Trying this resulted in:

Setting up virtualbox (4.3.18-dfsg-1) ...
insserv: script virtualbox: service vboxdrv already provided!
insserv: exiting now!
update-rc.d: error: insserv rejected the script header
dpkg: error processing package virtualbox (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of virtualbox-dkms:
 virtualbox-dkms depends on virtualbox (>= 4.3.18-dfsg-1); however:
  Package virtualbox is not configured yet.
  Package virtualbox-4.1 which provides virtualbox is not installed.

dpkg: error processing package virtualbox-dkms (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of virtualbox-qt:
 virtualbox-qt depends on virtualbox (= 4.3.18-dfsg-1); however:
  Package virtualbox is not configured yet.
  Package virtualbox-4.1 which provides virtualbox is not installed.

dpkg: error processing package virtualbox-qt (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 virtualbox
 virtualbox-dkms
 virtualbox-qt

so it looks like I will need to purge everything as you said and reinstall

Bob