Oracle VirtualBox has recently reached the release 4.3.18. For Ubuntu Unity, the full-screen mode and multi-screen issues has been fixed.
Oracle announced an update for VirtualBox 4.3 on the last Friday. For Ubuntu Linux, the issue that Unity panel and Launcher overlay the guest screen in full-screen mode has been fixed. The new release added possibility to use legacy full-screen mode as the new one can cause multi-screen issues under Unity.
Read the changelog at: www.virtualbox.org/wiki/Changelog
Install Virtualbox 4.3:
Check your OS type, 32-bit (i386) or 64-bit (amd64), by clicking on option “About This Computer” from shutdown menu (top-right corner gear button).
Then download and double-click to install the package from the official link below, previous installation need to be removed.
To receive future updates through Software Updater:
1. Press Ctrl+Alt+T on keyboard to open terminal. When it opens, run the commands below to add the official Virtualbox repository for Linux:
sudo add-apt-repository "deb http://download.virtualbox.org/virtualbox/debian trusty contrib"
you may replace
trusty for Ubuntu 14.04 with your Ubuntu release code name.
2. Then get the key:
wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
3. Finally check for updates via Software Updater.