Is the process you mention any different than launching the TAPIMgmt tool and adding users that way? It appears to be identical.
If so, we always run into an issue when associating users with TN's. Here's our scenario:
We utilize free seating which allows any user to sit at any TN and log into Symposium. To make this work, we associate every call centre agents LAN account info, with every TN. So, for example, if you look at any TN, you will see approximately 150 users associated to it. When a new TN is created, we right click on the TN, choose "Edit Users", then click "Add", confirm the container is pointing to the Domain our users are in, and then we copy/paste a large text file containing all of our agents (example: jdoe; jsmith; wgretzky; etc etc). The names get resolved, we click on OK and voila.. the TN now has all users associated.
Here's the problem.. if we try to add/modify users on another TN after completing the above, TAPIMgmt freezes up to the point you have to End Task. If you launch TAPIMgmt after the End Task, typically we find that the TN's are no longer displayed, and we end up rebooting the server. Naturally this is a huge pain, and therefore we only make changes after hours. The workaround we use is to add/modify 1 TN, close out completely from TAPIMgmt, then relaunch TAPIMgmt and modify the 2nd TN. Rinse and Repeat.
Please tell me there is an easier way to add new users to existing TN's, and existing users to new TN's. This can't possibly be the way it's meant to work?
Sorry for the essay.. just wanted to explain myself as best I could.