I finally isolated the problem! It was a sneaky little file that had been hanging around from someone's UI mod that I uninstalled when I switched to a different one and overlooked it.
Those extra files added onto mods can sure trip you up when you switch mods if you don't get them all deleted. LOL
I never could get the coinweight window to autoload using either the mainhud_player.xml file or the mainhud_clock.xml file, but when I stuck it in the mainhud_mainchat.xml file, it worked like a charm. I have NO idea what the system's objection was to either of those files, but both the compass and the mainchat files were perfectly acceptable.
