No, I haven't altered anything in my UBB. I tried uploading the public_common.pl from the original file but that made no difference whatsoever. I downloaded 6.7.2 but never upgraded from 6.7.1 At this point, I don't want to do anything more until someone with UBB savvy tells me the best route to follow.
(I tried to close the forum with an updated "closed" message to let my members know what was up, but even when closed, the forum pages generate those &$@## "Infernal Server Errors")