Duplicate email approval notification

A couple of our users are getting duplicate email notifications to approve a single purchase order.  Time stamp is identical on the email.  I checked who's who set up and it appears to be set correctly, no duplicate workflow entry for the users.  Has anyone else come across this issue?

What did you do to fix? I Ruled out any issue with the approval set up.  No delegating going on.

Thanks in advance for any help.