I'm having an issue with Rotation.
This is strange. I had a 2007 Quad MacPro 2.66 with a 30" primary run from an NVDIA card and a Dell 17" Rotated display on the USB with DL adaptor 1.3b3. The rotation was fine even after updating to 10.6.7.
A week later I have a new 6-Core 3.33 MacPro, same everything except standard ATI card on the 30". The USB monitor still works, but I cannot get "Rotation" to appear in the Displays control panel for the Dell, so I can't use the monitor rotated. On the "Display" tab it just gives options for Refresh Rate--no rotation. Rotation is only available now as an option on the primary monitor.
Uninstalled/Reinstalled the driver, and ran the full gamut with Onyx, and even trashed finder.plist and systempreferences.plist and tried to replace them with my "Time Machined" ones from the old computer. No diff.
Now I am S.O.L....