Hi
The final solution to my problem - which I am sure many Linux users will perpaps find obvious was :-
Determine the XFree86 config file via the /var/log/X* file.
I edited this and found, no surprise, a monitor section for my prevous (CRT) monitor.
I rebooted - and at GRUB entered 3, booting non-graphical (I presume run level 3?)
I then logged in as root and ran sax2. This whirred for 30 seconds and then was done. Examination of the X config file showed values now present for the AOC. Rebooted and all was fine.
Thanks for help and suggestions.
Halian