Active Playlists not working right?

I've setup a Active Playlist as follows:
- "By Date" Active Playlist around Year
-- Sub-Active Playlist around Month

I've also checked the item 'Only list files at the lowest level of active playlists'.

But when I navigate to "By Date", it lists 2008, 2009, 2010, 2011, but also lists all the content from the sub-folders (which is a lot of content!). If I navigate inside a year "By Date"->"2008", then I correctly see the months and not all the 2008 content.

How do I stop all the content appearing in the "By Date" parent active playlist?

It's a known issue in the current release of Mezzmo. It has already been fixed in the upcoming update, so next release of Mezzmo will have active playlists working properly. Thanks for reporting this issue!