No idea what a Catalyst is. The VPN itself is a mystery - I have no idea what it is and have no access to it. I thought about sockets (and ports) but the network/clients local to the server are fine. The traffic will be Telnet - nothing complicated. I've disabled a new feature in Service Pack 1 that tries to thawt SYN attacks (not entirely sure what these are). It might also be needing a hotfix - will have to check his on Friday though.
It bothers me when I can't fix things - I have a failure complex