I'm wondering if there has been any further discussion on this item. We are seeing this occuring in our Moodle Installation as well. Similar to Kathleen's issue, the scenario that we have seen is that when a course is copied - these system level questions duplicate. Here is some additional questions that we have seen.
First Observation:
There are scenarios in which a course is built in a staging environment and then questions are exported from staging and imported into our production environment. My understanding (limited) of backup and restore is that on version 2.x when a course is requested, the backup process will create an XML file of all the potential questions needed for the course (among other things). During the restore process - the restore will look for the question id and stamp. If they match - great. If not a question is inserted.
Could the stamp on a question be incorrect if imported from a different environment? Or - what exactly is being compared? As only questions that we have modified get duplicated. In looking at the questions in the key_question table - The stamps between the edited question and duplicates are the same, but the version is different (as I would expect). What is the question version being compared against?
Second Observation:
If we are editing a system level question while a course is being created, duplicates seem to get occur. Not just where we were editing, but across the course. Could the record locks be occuring during the course copy that does not allow for the query/compare to complete successfully that could cause a question to get inserted? I wouldn't think so - but just not trying to rule anything out.
Thanks for any information you could provide.
Bob