I upgraded from ubuntu 12.10 to 13.04 on a laptop running an ATI RV635 [Mobility Radeon HD 3650] graphics card. After the update the screen was garbled. If I get into ubuntu via the ubuntu recovery console (network enabled option) I can log in but then see no Unity or decorated windows.
When I upgraded from 12.04 to 12.10 I had to follow the instructions at http://www.ubuntuvibes.com/2012/10/how-to-install-amd-catalyst-legacy.html to use my display but these didn't work for 13.04 and I undid them.
Can someone please help me fix this display issue so I can use 13.04? The Software Center says the open source driver xserver-xorg-video-radeon is installed so I don't know why that doesn't appear to be working.