[curt.clifton]

Date filtering and grouping is broken somehow. It quite often behaves strangely for me as well. I've submitted vague bug reports on this, but haven't been able to nail it down to something consistently repeatable. It seems to be related to leaving OF running for long periods. I've taken to restarting it a couple of times a day.

You might try doing a database Backup and Restore to force OF to take a fresh look at the dates.