Arghh! Sorry - I now notice a button in the calligraphy toolbar (an
arrow on a slope) to "Use the pressure of the input device...". Once
this is enabled, the devices dialog then works as expected.
Could the pressure drop-downs not be greyed out, and a "Use the pressure
of the input device..." button also be included in the dialog?
I also notice the puck is now listed after restarting inkscape, and it
is actually drawing somewhere offset to the right and down (was out of
the visible area).