After a reboot, it's gone back to another res. I still can't find out how I caused it to go to 1980 x 1080.
Even the Advanced list does not include that res.
Pain in the
Ages later.
I footeled with it for ages, then installed soft that wouldn't run with W7. Then after about 20 times of going to the res options, suddenly, there was 1980 !! But, the option for a higher refresh was withdrawn at this line frequency.