Hi Bob,
I've tried selecting other monitor resolutions, as I thought of that also. But my current resolution is the only one that actually fits my screen, so am assuming that it's the correct size for this monitor.
It doesn't help that I technically have a TV screen rather than a computer monitor, but that's work for you, and it isn't going to change any time soon.
It's definitely stretched. I work in design, and it's definitely not showing at the right scale. I don't have this problem at home.
PDFs also appear stretched.