Comment 15 for bug 245383

I am seeing this problem as well, on both Hardy and Intrepid. Hardy worked fine for me until an upgrade about a week ago. Attempting to get away from it, I moved to Intrepid, which also shares the same problem. As with others, starting up gnome-termina, mozilla, or most any other application causes the dual-headed attached lcd monitor to flicker or blink, for about one second. Transitory windows, such as run application, do not cause the problem to happen.

The hardware here is a Gateway laptop with a Intel Mobile 945GM with a 1280x800 LCD and an external monitor at 1680x1050. In order to get dual heading to work, I added a Virtual desktop setup to my xorg.conf to five a resolution of 2960 x 1050.

#ubuntu+1 hints that this is possibly a problem with xrandr or load-detect, and isn't unique to NV, so this bug will probably get merged in with something else soon.