One of my users is trying to update a Contact record. OWD is Public Read Only on Contact. Grant access using hierarchy is checked. The user sits higher in the role hierarchy than the record owner. The user's profile has Create, Read, Edit, View All perm on Contact object. 'Insufficient access rights on object id' error shows up when that user is trying to edit a record. I am ruling out problems relating to other related objects because when I add that user to a Modify All Perm set for Contact for testing purposes, that user IS able to edit that record. Of course we do NOT want to grant that user that access. What am I missing?