Today users should update to 10.5.5

If you are a user of Today, I would highly recommend updating to Mac OS X 10.5.5 as it has many fixes to the CalendarStore framework. CalendarStore powers the database behind Today. The biggest bug that is known to be fixed involves detached, recurring events not being displayed properly. This now looks to be resolved.

You can update to 10.5.5 by going to the Apple menu and selecting "Software Update."