Internet access problem across Win/UNIX network with static IPs

Hi

Network consists of XP-home, 2000, NT, 98, SUN, Linux, OpenVMS with the XP machine having the connection to the outside-world via DSL.
We have been using Static IP's due to the existence of the SUN, Linux (and sometimes Alpha/OpenVMS).
All was fine until we got hit by a virus and had to re-install XP and chose to upgrade to XP SP2 for added security.

Now, if I continue to use Static IPs, all machines can see each other and fileshare, but I cannot get to the internet on anything except XP.
If I run the Network Connection Wizard on the XP and let it choose an IP address and set the others to 'Obtain IP address automatically', then I can fileshare and get at the internet, but then I lose my connections to the SUN/Linux/OVMS machines.

I've looked at many posts here and have tried setting the XP address as the default gateway and setting the two DNS server addresses from the ISP, but no joy.
I've tried browsing to direct IP addresses such as http://66.102.9.104 but no joy.

Anybody have any ideas?

with XP SP2 there is adda a firewall.
try disable it.
it its located in "control panel"->"windows firewall"

it is possible to set up the firewall to allow internet sharing, but do it only if you not already have another firewall