Sorry, I guess I forgot to be a bit more accurate with what I said.
The 3-Com Firewall's themselves do the authentication and IKE. It doesn't amtter what the OS is on either end as it isn't the OS that is setting up the VPN. My "cunning"

ploy was to use this so that I didn't have to set up RAS or anything else on my server (win2k server, FYI). The VPN Upgrade for the OfficeConnect Internet Firewall 25 comes with a VPN client (SoftNet PK from Safenet, if I remember right) which I upgraded to Soft-Remote when I had problems initially. That didn't make any difference. The laptop to office VPN is initiated on the laptop with a ping to the LAN ip of the office firewall and the soft-remote initiates the vpn from this. It works fine when the laptop is on a DUN connection to my other ISP (Plusnet) but when I am on another lan the tunnel is created (the logs show this) but nothing will go through it.
The Firewall to Firewall VPN is initiated from my house by pinging the LAN ip of the office firewall. The house Firewall log shows that the IKE has been initiated but it never appears on the office firewall.
Hope this makes sense to someone 'cause I am fed up of staying in the office till 3 or 4 in the morning - the whole point is that I can come home and carry on working from here when I have to.