i'm using gnome shell on an asus eeepc (atom N570, 1Gb ram, opengl renderer mesa DRI intel IGD). As soon as i connect my external monitor, i get garbage on both screens. When i disconnect, the display goes back to normal.
I think i had kind of similar issues with unity 3D, where i got a message telling me that the resolution for the extended screen exceded the maximum one supported by my hardware. In that case i could choose to lower the resolution, clone the displays, turn of the eeepc's one. Here i seem not to have control at all, since the switch happens when i connect the cable.
What can i do? Is there a solution (which doesn't involve dropping gnome shell)? thanks!