On Demo if you go to this record http://d46.demo.civicrm.org/civicrm/contact/view?reset=1&cid=202 and 'add address' or 'Edit' and save the Home Address with just Country (currently set to Default Country = Australia), nothing gets saved, no debug message either.
I tested on demo after witnessing what I thought was a problem with a Profile on a Contribution page, but the issue seems to be actually with the 'save contact' task.