Here is the solution.
Guest Additions in Oracle Virtual Box 4.3.6 version somehow conflicts with Ubuntu 14.04 LTS.
Warning: unknown version of the X Window System installed. Not installing X Window System drivers.
Do not dig in for help on the internet. Just use Oracle Virtual Box 4.3.28.It worked for me.
The WordPress.com stats helper monkeys prepared a 2014 annual report for this blog.
Here’s an excerpt:
A San Francisco cable car holds 60 people. This blog was viewed about 410 times in 2014. If it were a cable car, it would take about 7 trips to carry that many people.