I'm trying to set a SmartFolder in Calendar, to periodically show me all my calendar entries that have no reminder (so that nothing sneaks up on me). Weirdly, when I set the search criteria as "has no reminder", the list still contains some items that have a reminder. The screengrab is here:

https://dl.dropboxusercontent.com/u/23232804/ForReview/screengrab.jpg

you can see the little bell symbol next to some of the ones this finds. What am I doing wrong?