this has been happening for a while but I never got to report the problem properly. In brief, the problem is that after watching a video in gnome-mplayer on an external screen for several minutes, the screen would blink and twinview will go into clone mode. This is how do you get there:
- plug in an external screen into the DVI output
- start nvidia-settings, detect displays and enable the screen to be on the RHS of the laptop panel
- start watching a movie in gnome-mplayer (it uses vdpau output)
Then the screen will go into clone mode - maybe it has something to do with screensaver. This is on Fedora 16 x86_64, on a Clevo P150HM laptop and Gnome-shell 3.2, but I was observing similar problem with Fedora 15 and gnome-shell 3.0 too. These packages might also be relevant:
$ rpm -q mplayer gnome-mplayer xorg-x11-drv-nvidia
I am attaching nvidia-bug-report.log, the issue mentioned above has occurred twice during the X session. After the first one I rearranged the screens using nvidia-settings and got back to the original layout.