Issue with Role Management

Hi,

We have sorted the entries of our customers within folders in alphabetical order. For each letter of the alphabet there is a folder, from A to Z.
Within these folders customers with the same initial letter are stored. So "Toys'R'Us" is under the folder "T", "Verizon" is under "V", and so on. We defined separate security groups and roles, the roles are each linked to their Active Directory Group pendant. Roles are tied to one or more Security Groups.
We now noticed that one of these roles is assigned to a wrong Security Group and we would like to change this. Within "Role Management"
all selections (View, Add, Edit and Delete) are removable (at least it seems to be), also when applying the changes by pressing "OK" no error appears,
all seems to be okay. But when one does re-open the "Role Management" thereafter, the selections are again the same (selected) as they were before we changed them.
The change is thus not saved and we were not able to correct our misconfiguration. But when only the selections Add,Edit and Delete are removed and not the
"View" selection, the change is saved.

I did read of another similar issue on this board, there the error was "inherited". Thus I did check the overlaying folders for such settings, but no
Security Groups Settings are inherited in this case. The same goes for the actual customer folder, there is only one Security Group.

Also when creating a new Active Directory Group, adding a new role within RDM and assign said Security Group and then
re-open the "Role Mangement" all four selections are selected for the undesirable Security Group to which we didn't assign the permissions
in the first place.

If anybody could point me towards a common gotcha or something I could check that I have overseen, I'd be grateful for all your support.

Kind regards,
Simone