Quote Originally Posted by brian.farr View Post
Having not heard of "guest additions" is meaningless to me, please can you expand.
Which means you haven't installed guest additions. A VirtualBox guest OS is about the most irritating and user hostile thing to use unless you install guest additions. You install guest additions in the guest OS - that is, in Ubuntu.

The instructions for installing guest additions are in the user manual. The pdf for the manual will be somewhere in your Mac filesystem but it's been so long since I installed VB on a Mac, I can't remember where. If you double-click on the downloaded dmg installer, the pdf might be viewable from the Finder window that opens. Failing that, you can download and/or view the manual here:


Under the heading User Manual, the left link is for the pdf.