After a fresh upgrade to 13.04 I found two problems (so far). When I open a desktop instance with vncserver, the mouse actions don't work. However it shows the movement of the mouse. When I land on a "close" or "minimize" buttons it shows a double arrow either horizontal or at 45 degrees. I know that is not the client on the other side because I use it with other systems (e.g. Centos, XP) and it works well.

Also, every I log on the system with a terminal I get the message: New release '13.04' available - Run 'do-release-upgrade' to upgrade to it. It does not go away even if I run the command again.