AzDude, I have more details to add to the issue that I have discovered while tweaking at it over the weekend. The issue seems to be that several setting in the Global options drop down are not actually executing correctly. And when I select the "broken" ones and then reopen the Default property tab that are actually saved as a different position setting. In the thumb nail this difference is also reflected on any wallpaper that doesn't have a specific alignment set. These "remapping" do not happen when one of the settings is specifically chosen for a specific wallpaper. It also doesn't matter if the background is animated or not.
Working settings appear to be: Auto Scale, Stretch, Tile, Centre (Why the Canadian/UK spelling?), Fit, Fill Middle
Fill Bottom actually saves as Fill Top and Fill Top actually saves as Stretch.
It's as if somewhere there's a configuration that has the wrong metrics (graphical manipulation) assigned to the wrong labels.