This bug affects me too, I have an ATI Mobility Radeon HD4650 graphic card.
I don't have any other dock than the Unity one.
The symptoms are exactly the same : when I log in Unity 3D with LightDM, I have a black screen with small rectangles of the regular wallpaper. I can click on the session menu ang logout, but I can't access any other indicator.
This bug affects me too, I have an ATI Mobility Radeon HD4650 graphic card.
I don't have any other dock than the Unity one.
The symptoms are exactly the same : when I log in Unity 3D with LightDM, I have a black screen with small rectangles of the regular wallpaper. I can click on the session menu ang logout, but I can't access any other indicator.
Unity 2D session is working perfectly.