Filed Does not Exist' exclusion in customized Outlook Contact tab

[bankerIT]

I created a cutomized tab in Outlook to capture contact information using 'yes/no' check boxes. In using Advanced Find to exclude contacts that were marked 'yes', I found that a number of other contacts were also excluded even though they were not marked 'yes'. Upon investigation, the subject field, when viewed in 'phone list' view, has a 'unchecked' box present which is being perceived as equivalent to a yes by the advanced find feature.

Ay suggestions or how to return the fields to their basic state such that a test for "field does not exist" does not exclude the associated contact?