XP networking problem

Hi. I’ve had this problem for some time. We have a win2k server, one xp pro, the other computers are win98. Everytime the xp computer is rebooted, none of the win98 can access it until I run the network setup wizard to add it to the network.
After that everything is fine, until the next reboot. Although the win98 computers can’t browse, they can ping the xp computer, both by ip and computer name. Any idea why this is happening and what to do to solve it? Thanks