I guess posted this wrong somehow because I don't see it in the list of topics associated with this plugin. But basically I have a recurring event that is set for Mondays but it shows as Monday and Tuesday on the Calendar view for both the Month and Week view. I have also seen it add an extra day in the calendar for a non-recurring event that lasted a month. On that one it also added one extra day.
Here is the caledar page:
and here is my original forum post: