Teamsite over VPN

System

Trying to run Teamsite over a VPN. Seeing varying degrees of service when accessing Teamsite over vpn.
TS version 5.0.2 on Win/NT and Nortel extranet client to form the tunnel with a 4000 Extranet Switch.
When uploading and downloading files the operation sometimes completes but sometime will just hang when trying to edit a file.
No error messages seem to be generated.

After attaching a sniffer to the network this is what is seen,

Requests a connection to the Teamsite server (SYN)
The Teamsite server responds and a connection is established (SYN ACK)
Data is passed back and forth between the server and user
The Teamsite server requests a TCP disconnect (FIN)
The user acknowledges the disconnect but does not reciprocate (ACK with no FIN)
Terminates the connection (TCP RST)
Requests another connection and the process starts over again
questions,
1. Is this normal connectivity?
2. Was Teamsite designed to work over the VPN?
3. Is there an update to the plug-in that the users are using?
4. Does any have Teamsite working correctly over VPN?
5. Is this supported?