Lookup Criteria

Lookup Criteria

 I have this form to match individuals already matched with project onto a second project.  So I've based a lookup on two criteria, both of which must be met, that reads something like this:

(Match != null) && (Second_Match == null)

I just KNOW there are records in my database that meet this criteria, the form selected is right, but no matter what I do, the dropdown is empty.  

why won't it work?