The fact that Win 98 can successfully map the Samba shares based on your logon.bat file & XP can not hints to me that the problem is not with the way Samba is setup on your Linux server but with the way the XP boxes are accessing the network. The XP network does work slightly differently from Win 98 but basically XP still uses all the same protocols & procedures that Win 95 used all those years ago.
Post your results of the following:
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From one of the XP boxes, can you navigate to the Linux server via Network Neighborhood?
From one of the Win 98 boxes, can you navigate to one of the XP boxes via Network Neighborhood?
From one of the XP boxes, can you navigate to one of the Win 98 boxes via Network Neighborhood?
Are you running the "Home" version or the "Professional" version of XP?
Have you installed any of the XP "Service Packs"? Especially "Service Pack 2"?
From one of the XP boxes, open Windows Explorer (the Windows file browser) & enter one of the Linux paths into the "location bar" (the place at the top of the window just under the icons that displays where in the filesystem you are currently viewing) For example type:
into the location bar. This should allow you to view this Samba share. (if you don't know what a "Samba share" is, go to
http://us3.samba.org/ or see the smb.conf man file: man smb.conf)
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XP also has a crappy, built-in firewall system, especially if you have Service Pack 2 installed. This might be blocking connections from the Linux server.
Also, post your /etc/samba/smb.conf file from your Linux server so I can take a look at how it's options have been setup & how the shares are setup. One thing that XP does differently from Win 98 is that it uses encrypted passwords by default where as Win 98 uses plain text passwords, this is something that can be overridden in /etc/samba/smb.conf.
There are many, many reasons that this might be happening... After you try the above, answer the questions & post your results, we might be able to narrow them down.