I really really wanted to find and nail http://bugs.sakaiproject.org/jira/browse/SAK-1307. We had such a fun weekend with the DAV-crew that I wanted to get this wierd one for the folks at Yale and at UM. So I instrumented a bunch of the notification code and went on the warpath.
The good news and bad news is that I couldnot reproduce it :( So I put in my debug logs for storage.