You can file this under D for Duh.
I figured out the problem with Firefox and Ancestry.com’s image viewer. It was the stupid Norton toolbar that automagically installed itself with FF. I really don’t appreciate that Norton did that, without any instigation from me. I uninstalled its sorry ass, and now all is well in vital document viewing land. w00t! This means no more Internet Explorer BS, which makes the baby Shelly very, very happy.
Now, if the databases I exported from the earlier copy of CFT on the old machine will load properly with the new copy of CFT on this machine, all will be well. The first one is taking its sweet fancy time, and I am not the princess of patience.