Have had issues with both the freecycle group and catvet.As I've mentioned before, I abhor the "Override: Unmoderated" setting for members' Posting Privileges - if this is what you meant for most users.
To achieve the effect you're after I would recommend:
New Users Moderated: checked
Unmoderate After: Not enabled
This way members start off moderated, and it takes your explicit individual action to unmoderate them.
If you "unmoderate" them by selecting "Default Group Policy" (instead of the override) then you retain the ability to put a stop to a flame war or any other form of disruption in the group by simply checking the Moderated box. After things calm down you can restore the group to the normal condition by taking the check mark back off.