Do *Not* Update eclipse installed from Ubuntu Software Center

This will completely screw up your eclipse installation. All of your plugins will be there, but not working.

[UPDATE 2013-03-05] If you are determined to update your eclipse installation from within eclipse, or if you just want to separate your eclipse installation from the Ubuntu software repository, then you should consider installing eclipse on Ubuntu as add-on software. Trust me, in general you will be much happier!