please help

This is a really strange problem, if anyone has had this please
let me know.
At work we have a intranet linksys router with 5 switches
(and one daisy chained hub) that connects 7 peer to peer
nodes with each other and the internet.
Everything works great except out of the blue about
every 3 days this one particular Win98 node will not
be able to plot to the print server nor can he se us. All the
rest of the nodes are WinXp and the print server is
Win2000Pro. We can see him but he cannot see us.
If he reboots then it fixes the problem. Except once it
did not and that time we could not see him either.
That time the problem spread to another WinXp node.
We turned off the power to the linksys router and turned it
back on, and then rebooted the two nodes and the problem
went away. But every two days or so the problem of the
one win98 node comes back. And then about a week ago
we started also getting a new message on the Win2000 print
server node at the same time that the win98 node would drop
off the network. The win98 node would simply state
"could not access printer, port not opened",
while the win2000 print server node would say
"An IP address conflict has occurred, please contact your
network administrator".
We don't have a network administrator. We set everything
up our selves out of the box.
Well I click OK on the print server message and it still
prints ok but there is something going on here that none
of us are experienced enough to decipher. Can anyone give
me a clue what might be going on?

 >"An IP address conflict has occurred, please contact your
 >network administrator"

I think this means 2 machines on the network have the same IP address. As this
doesn't always happen I assume you're using DHCP from somewhere and that's
what's causing the problem.

I don't know much about DHCP servers so until someone else comes up with a
better aswer I suggest you change some of the settings on the DHCP server -
range of IP addresses given out etc.<!-- ~MESSAGE_AFTER~ -->