I have several event modules on my site that are all set to display tooltips for the events whether they are in calendar or list form.  Within the same module, some events are displaying tooltips and some are not.  What would cause the tooltip for an individual event to not display when the module is set to display tooltips?

www.montereychurch.com -- look at Special Events on the bottom left.

It's not isolated to events from a specific calendar, recurring events, events that I added and then edited, events that are inherited from another calendar, events with potentially problematic characters in the title (& or " or '), or any other common trait that I've guessed at.

I don't have the version # of the events module in front of me, but I can look that up later if that matters.

Jonathan