I realize this is an old thread - but it's the closest thing to my same problem - maybe I'll get a reply? I have been functioning fine in Quark 7.5 working on OS 10.6. (That's Snow Leopard, for those of you who are cat callers). About three days ago I stopped getting the warnings when I "save as" to update a file in a new location. I agree with the previous poster that it's a slight time savings...assuming you know what you're doing, but I do miss the confirmation before a possible boo-boo.
With no new updates or software changes, why would this stop working randomly after functioning accurately forever?