Yes. I just repeated the procedure with a fresh mind on a fresh day.
The behaviour is just the same - when you press calibrate, calibrate, 1-port the frequency range always resets to 100khz to 3.2Ghz.
Subsequently pressing Frequency, setting the range up again leaves no option other than to press measure, calibrate etc etc and the same thing happens again.
BUT this time, the third time around while staring somewhat exasperated at the screen I had a hunch and pressed the screen region over the "100khz" under the graph and was delighted to find a little keypad pop up which allowed me to change the start frequency. Then I could do the same with the end frequency. Now I can continue calibration without actually having to press "calibrate" again (which would reset the span).
So problem is resolved.
I don't normally use the touch screen much (don't like fingermarks!) and am bemused at the behaviour wherebye the SVA resets the frequency just by pressing "Calibrate" button. You can call this a bug, or a feature. Regardless, there is nothing of this in the manual and I trust it is of help to others who want to do the same thing. I'm not very experienced above a few hundred Mhz but from how twitchy things seem to become I would have thought calibrating a VNA in the range that you intend to use it is mandatory every time.
I was going to add that my instrument started out life as a SSA but everything I have read and what I understand tells me that this couldn't be responsible for the forementioned "bug/feature".
Thanks for taking the trouble to look, and if someone else could verifiy what I have found it might be nice.
Cheers
Eloso