Was I missing some direction?
Great - pleased it's up and running.
I believe Virtualbox sometimes needs to (for want of a better term) "rebuild" itself into the system therefore a reboot often helps - I find it useful especially after any large update and VBox installs.
If memory serves - one time when I added a new kernel and rebooted one of the items I noticed being "rebuilt" - along with various other modules - was virtualbox therefore I tend to reboot after I install it.
Not certain whether any of this is actually necessary but a reboot often cures minor niggles plus I find it helps keep my systems nice and tidy (and refreshes memory)