I have a user that is checking permissions for a site, and she cannot see certain groups.
The groups that she is attempting to view members of are owned by group that she is a member of. (I just set that ownership relationship up on all those groups.) She can see some, but not all of the groups that she should have rights to see.
When I add her as a Site Collection Administrator, then she see all the groups (of course).
What could be causing her not to be able to see some of the groups?