Adding the RandRRotation option in the Screen section of /etc/X11/xorg.conf allows rotation on my nvidia card.
Section "Screen" ... Option "RandRRotation" "True" ....
Adding the RandRRotation option in the Screen section of /etc/X11/xorg.conf allows rotation on my nvidia card.
Section "Screen"
...
Option "RandRRotation" "True"
....