I am running ver 1.04.07 of formidable pro and found that the unique field checking is not working correctly. It has several problems.
One is that if you have several different fields that must be filled out, but you don't fill some of them out and you also make two fields identical that must be unique, then it only warns you about the blank fields. Upon fixing the blank fields it then allows you to submit the form even though the “need to be unique” fields were never fixed (and it never warned you).
The other issue is that sometimes it correctly catches one field as needing to be unique (if you don't leave blank fields) but missed another. Other times it told me I had to make one unique even though it was unique.
I can link you to the form if need be. This was a pre ver 1.04.07 form and I have not tested it with a new form but I may do that. Thanks for looking into this as this is one feature I really need.