Here' s the bug report. I could not restart X with only the DFP display enabled.
The configuration reverts to twinview. Looks like CRT-0 is required at all times.
I forgot to mention, we also tried with Suse 10 on the first desktop and had the same behavior.
I cannot remember the driver version but it was 1-0.96xx.
Initially I suspected the hardware but now we are working on untouched
hardware that was working under Windows XP just before installing
Ubuntu. (I was about to say that the desktop was working well under
XP... gulp, the system is 2-3 times faster with Ubuntu