When I install the Cisco VPN Client 5.0.00.0090 on my Vista laptop while connected to my office LAN it works fine. When I go home and connect to my home LAN I get the Reason 442 error. If I uninstall and reinstall while connect to the home LAN then it works, but when I go back to my office I get Reason 442 again.
I have added the line UseLegacyIKEPort=0
to my profile.
I didn't have this problem when running WinXP.