Forgot to answer this one from Lawrence Harris:

"...I have no problems getting DSS images into Guide, but when I select a
star to check its magnitude, I often find that another star is selected,
usually of much brighter mag. Does this mean that most stars on the DSS
images have not been measured yet? Surely not?"

Most of them _have_ been measured in A2.0, or GSC-2.2, or B1.0.
You can download the first two through the "Extras... A1.0/A2.0 Data"
option, and I'll be adding an option to download B1.0 in the next
update (thanks to John Greaves, who figured out how to work around
some oddities in the B1.0 server.) But if all you're showing is
GSC, then yes, DSS will show a _lot_ of "uncatalogued" stars.

-- Bill