I updated to Ubuntu 12.10 using the Update Manager in Ubuntu. ("A new version is available ...") GRUB was broken and I think I managed to fix this but still the Graphical output looks super weired: (The Unity sidebar is lost and I had to start firefox through the terminal [STRG]+[ALT]+[T])
I already tried some apt-get with fglrx, gdm & ubuntu-desktop but nothing changed.
Graphics card: Mobility Radeon HD 2600