Gnome 3 dual monitors doesn't work in Ubuntu and Debian
In Gnome 3, dual monitors don't work very well for me, both in Ubuntu 11.10 and Debian testing ("wheezy"). I do get a secondary monitor that looks different from my primary monitor, but can't drag any windows onto it, except for some non-Gnome windows (like Chromium browser), which I can drag onto it only partially. So the secondary monitor is almost completely useless.
I suspect that it has to do with my specific computer, because I have with two different OS's and with two different secondary monitors. I'm using an HP 6930p notebook.
How do find out what is wrong? Where do I start looking?
Thanks a million,