Win98SE and WinXP Pro File Sharing Problem

Up until a few days ago file sharing worked fine on my home LAN between a
Win98SE machine and WinXP Pro machine. The problem I now have is that while
the Win98 machine can access all the shared folders on the WinXP Pro
machine, I can no longer access files on the Win98 machine from the WinXP
Pro machine.

Upon opening view workgroup computers I can see the icons for both the
Win98SE Machine and WinXP Pro machine, however when attempting to access the
icon for the Win98SE machine an error message like the below is displayed.

"//computer_name not accessible. You might not have permission to use this
network resource. Contact the administrator of this sever to find out if
you have access permissions.

Incorrect function."

I can successfully ping either machine from the command prompt on either
computer. Any idea if problem is originating from Win98SE machine or WinXP
Pro machine? Any help with resolving this issue would be greatly
appreciated.