Hi,
I have Opensuse 12.3 installed on a Dell Vostro 3550 laptop with a Radeon graphics card running the default driver installed and KDE desktop. When I plug a monitor into the laptop a dialog box comes up where I can set the properties of the screens which works perfectly, but after about 5 to 10 minutes either the plugged in monitor will stop working and flip back to the laptop screen or vice versa. This happened with Gnome on Opensuse 12.2 as well, with both the propitiatory drivers and the default Opensuse drivers. Any help would really be appreciated!