Description of problem:  I have a Dell Studio XPS 13 with an Nvidia 9400M card. I connect an external BenQ LCD panel via an HDMI-to-DVI cable. This has worked in previous Fedora releases.  But after a fresh install of Fedora 15, the monitor gets a signal and shows plymouth, then the stripe wallpaper (login screen is shown on the laptop screen). However, after I log in, both screens (external and laptop screen) go blank and I cannot Ctrl-Alt-F2 to terminal, restart, etc.  I have to ssh into it from an external PC, kill Xorg, and then reboot (i.e. simply rebooting doesn't work, I have to manually kill Xorg first before it decides to reboot).


Version-Release number of selected component (if applicable):  

xorg-x11-drv-nouveau-0.0.16-24.20110324git8378443.fc15.x86_64



How reproducible:  Always


Steps to Reproduce:
1. Plug to external monitor using HDMI-DVI cable
2. Boot into Fedora 15
3. At login screen, log into Gnome3
  
Actual results:

Both external monitor and laptop screen go blank

Expected results:

I should at least see the stripe wallpaper on the external monitor

Additional info:

Note also that if I boot into F15 and log in to gnome3 without an external monitor plugged, its all fine, but once I connect the HDMI-DVI cable, both screens go blank.