I think this is a bug regarding setting the opt-in list Distribution Security Role for child portals. (Version 4.1.0.22051)

The Good

• In the parent portal, when the portal is selected, the values in the distribution security role dropdown change.
• In the child portal, the lists assigned to the portal are correctly shown.
• In the child portal, I can successfully set the distribution role.

The Bad

• In the parent portal, when the update link is clicked (whether or not anything is changed), any value that is set for the role is changed to "Administrators". The child portal lists' distribution roles cannot be successfully set from the parent, and any roles that are set in the child portal are reset in the parent portal.