I have NW6.5 server running BM3.8. I have a few users who use the Cisco
VPN client to authenticate to anothers companies network for support

They can authenticate fine. It's when they go to use PCANYWHERE remote to
access machines on the other network that the problem occurs. They just
can't get connected.

I have tried the process with the firewall down and it's the same deal.
Could it be some sort of nat issue. Remote machines that don't go through
the cisco tunnel are connected to fine.

I ran an ip trace which shows traffic during the initial authentication
connection going through fine on UDP source / Dest port 500. When the
PCANYWHERE traffic is traced it just shows (other).

Any ideas ?