Thanks much John! That gives me a good place to start. Like I say, I have no idea how I reached the current settings... I don't really have a firm understanding of the dimension properties, property values presets, or dimension styles.
I've only studied the doublecad training vids. They are good for showing you how to work in the program, but weak on structural concepts on how the program environment works. Probably not really aimed at beginners... Perhaps they should include a set of pre-sets for common working environs: US & metric architectural, engineering, etc, with all the common settings for type, lines & colors, arrowhead, etc already chosen for newbies.
I'll study the suggested help files, and see if I can correct my drawing. I'll keep you posted. If I can't figure it out still, I'll post the drawing and maybe one of you power users can easily spot my error.