excluded

I'm running vb 4.2.4 and I recently installed Super PM Pro (upgraded from lite to pro this morning) and I'm trying to create a usergroup that can only PM (send & receive) with the Staff and no other groups. When I going into the settings for Excluded I have it set as follows: Active = Yes...

ok my issue is when i set this to no Excluded From Sending PM's Active then i select the usergroups excluded i have allow to reply to staff to yes then i select my staff in which they can pm what happens then is this seems not to work i can still pm everyone even though i am in excluded...