Just updated to version 3.1 of the plugin.
I went to look at the calendar, and I do not see any of our published posts showing up in the calendar. In addition, none of the unscheduled posts are showing up in the right column.
What is a bit interesting, is that we are using the WPML plugin for post translations, and the only published posts that do show up in the calendar are the translated posts.
Not sure if this is a clue to the issue.