MS Access Database- Survey Issue

To whom it may concern:

I am working on a MS ACCESS database in which users take a simple "Yes" and "No" survey (See Attachment).  The survey use's Social Security Numbers as the primary key.  I realize this isn't normal, however, my military "customer" requires the SSN for this application, so I have no way around it.  I must use the full SSN.  The database application functions perfectly except for when a user has a "Zero" in the beginning of their SSN.  I have set the data type to text and the input mask is set to be a SSN.  I have provided the original database (See Attachment) where the SSN was originally a field named "PerticipantID".  This eventually became the SSN in the final application.  I migrated this survey application into my finished application with little trouble.  It wasn't until users started using the new survey, that I identified the issue, so I checked the provided original (See Attachment) and that too is having the same issue.  I had originally thought I missed something, but when I saw the original survey had the same issue, I realized is must be something else.  Note:  Anyone else with any other SSN or Participant ID other than one that starts with a "Zero" works just the way I wanted it to.  Any assistance you could provide after review of this survey will be greatly appriciated.

Edward J Kinlen
Survey-Database.accdb