I'm trying to install virtualbox-4.3 from software centre. But here showing an error message like this.
try to remove virtualbox before (in terminal try:
sudo apt-get remove --purge virtualbox
if you get an error that virtualbox is not found try this:
sudo dpkg --get-selections | grep -i virtualbox
then you should get a list of the installed packages with "virtualbox" in their name... remove them and try to install the new virtualbox version.
hope this helps!