TOPIC: Private Events - Category Permissions

Joomla 2.5.7 - DT Register 2.8.1
Trying to restrict event registration access by Category.

Joomla Users -
Created group Users A and group Users B - both are same level as Registered.

DT Register Categories -
Created Category A with access level set to only Users A and
Category B with access level set to only Users B.

The idea is that Users A can only access Category A events and Users B can only access Category B events. If I create a menu item for Users A only their events show up, but if I copy and paste a Category B event, Users A can access and register.

How can I keep these categories limited to the appropriate user group?