I am using Organic Groups to give group-specific content to users.
The groups' permissions do not allow simple group members to edit group content.
By using the Node Acess User Reference module I wanted to grant permission to specific group members to edit specific nodes on an ad-hoc basis.
The devel information that I get is that allthough that rule works, it is being overriden by OG's permissions thus still not allowing the user to edit the node.