I wanted to get rid of black backgrounds in Cairo Dock so I followed the official guide https://help.ubuntu.com/community/Lubuntu/Windows#How_to_control_window_opacity to install xcompmgr. After restart and logging in I have no desktop, only notifications. I can access terminal through [Alt+Ctrl+T]. How do I fix this? What went wrong. And above all - why is it that official instructions brake desktop?
Lubuntu 12.10 x64, clean Thinkpad T500 with AMD/ATI discrete graphics activated (and confirmed)