Why is this import running twice?

[extan1]

Thank you again, @deanhystad. I know these are not fun questions to answer (it wasn't fun to ask, either ;-). I really appreciate the effort you put into your thoughtful replies.

Somehow there is something about this process that still eludes me, but I guess that will come with more time. I've got it working at least, so that gives me a starting place to experiment... Exciting, after so many hours of frustration!