Description of problem: Dual Monitor in over/under configuration crashes


Version-Release number of selected component (if applicable):
 Fedora 17 64 bit KDE version, fresh install.


How reproducible:
Every Time


Steps to Reproduce:
1. System Settings -> Display and Monitor -> Size & Orientation
2. For DVI-I-2 change from default "Right Of" to "Below"
3. "Apply"
  
Actual results:
Crash: no mouse or keyboard response, screen usually goes black. Reset or poweroff required to recover.

Expected results: Displays change to over/under configuration.


Additional info:
 nouveau driver, twin 1920x1080 displays.
 32 bit Fedora 17 is good, 64 bit Fedora 17 crashes.
 "Above" and "Absolute" also crash; "Left", "Right", and "Clone" do not crash.
 In addition to crashing in KDE, Gnome and xfce also crash.
 When using openbox, there is no crash, but the configuration does not change and an error message appears:
  GDBus.Error:org.freedesktop.DBusError.UnknownMethod:No such interface
  'org.gnome.SettingsDaemon.XRANDR_2' on object at path /org/gnome/SettingsDaemon/XRANDR
  yum update Oct.21, 2012: no change in behavior.