help with error messages

[JonD]

I'm looking for help understanding some error messages.

Background:
I've been doing a lot of remote support for clients using VPN connections back to their office server.
1. Chunk VNC running as service
2. I log in directly to remote computer (typically a notebook)
3. I initiate a VPN connection on their computer back to their office
4. Typically InstantSupport connection drops (as I would expect because of the different path)
5. Usually I reconnect successfully over the new path
6. Frequently I need to close the VPN connection
7. Typically InstantSupport connection drops (again as I would expect)
8. Usually I reconnect successfully

However, there are occasions where the connection does not recover and there are 3 messages that I get and I'm not sure what they are telling me:
"Failed to get server address"

"Server closed connection
- server running as application"

A third message (paraphrased here")
"Another viewer using the ID"
In this case, I suspect that either the repeater or the remote computer thinks I'm a different viewer because of the different paths involved.
This seems to recover after a significant delay.

Any help to improve the reliability of the switching of connections in the above scenario or clarification of the messages would be appreciated.

JonD