CiviCase - problem assigning case roles with multiple clients

In 4.3 the 'Add Client to Case' popup dialog (pencil icon displayed when AllowMultipleCaseClients is TRUE in Settings.xml) is not working at all - so I can't test the behavior below. When I click done after selecting another contact the page reloads but the contact is not added as client for the case.

We should be adding relationships for multiple clients. Please investigate and fix both issues for 4.3.

— Original Post —
If a case is set up with multiple clients, and then a case role is assigned, the role is only "attached" to the client who is currently "active" in the Manage case screen.

Example: find a Housing Support case by searching on contact (client) A. Manage the case and assign role Homeless Services Coordinator.

Now find the same case by searching on contact (client) B. Manage the case and display Case Roles - the Homeless Services Coordinator is listed as unassigned.

It works in reverse too: assign a role when the case is accessed via client B, and that role will not appear in the case details for client A.

It appears as if, when a case role is assigned, the relationship is only created with whoever is the "currently active" client. Presumably what should happen is that relationships should be created between the incumbent of the case role and ALL of the clients in the case.

The above description relates to what happens when assigning a role in a case that already has multiple clients. There is a similar problem when adding an additional client to a case that has some roles already assigned - none of the pre-existing role assignments are attached to the newly added client.

(forum post here: http://forum.civicrm.org/index.php/topic,27891.0/topicseen.html)