Very strange '98SE networking prob

I hope some guru on here had an idea about this, I dont!
After many years of problems I finally managed to get ICS running on my
network with no problems, using static IP addresses and only TCP/IP
protocol. In this network theres a group of 4 PCs (all 98se) linked to an
unused 98se gateway PC (old naff one bumbling along under my desk) and each
other through a switching hub doodaah Well off and on I've had problems
with it but now its stumped me with the almight black art of networking.

ICS is working on all PCs (albeit with random hiccups of not finding web
pages every so often until you refresh, from any PC) but from PC number 3
(Call it James) I cannot see any of the other PCs - and unable to access
network when DC on entire network. The other computers can see each other
and even see James, they just cant access James. Its like it is only
recognising the network for the case of ICS, nothing else. My firewall
software seems to make no difference when I remove it.

Any ideas on this one?

Cheers
James