Win98 not seen by XP Pro over network

Just added new computer running XP PRO to network with 2 Win98SE machines. One W98 “A” and the Xp see each other fine. The other W98 “B” machine is only periodically seen by “A” and never by the XP.
“B” has had a lot of stuff loaded and removed over the last several years, and Win98 has been reloaded over the original several times. Any sugestions?