@Will A - am I missing something?  These are non-equivalent, so your suggestion won't work.
- 
		Not member of engagement program x.
- 
		Member of Engagement Program: True. Program is not x.
1 is what I need. 2 only matches leads who are a member of an engagement program other than x.
I need to write a "sweeper campaign" that finds leads with certain properties who are not a member of a particular engagement program.  The campaign adds them in to that engagement program.
I am finding that writing the filter I need (Member of engagement program: False. Program is x) does not work.  It returns no leads.
Do I need to submit a bug report, or wait for a fix, or am I getting it wrong? 
🙂