Thanks Brian,
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