Thanks Vigilante.
I am now able to access all the shared folders for all of the user accounts. I had to disable the sharing for all the user accounts (other than the administrator account, which had no sharing problem), then re-enable sharing from within each user account. In order to set-up sharing from within the other user accounts, I had to set-up the other accounts as "computer administrator." After enabling the sharing, I changed those accounts back to "limited."
I also added the IP address and subnet mask of the PC with XP Home onto the trusted computers listing in NIS 2005 (on the PC with XP Pro). This allowed me to "turn-on" the Norton Personal Firewall without losing any of the network connections and file sharing.
I still have another problem. When signing-in under the computer administrator" user account in the PC with XP Pro, I can see all the shared folders for all user accounts in the PC with XP Home. However, when signing-in under the "limited" accounts in the PC with XP Pro, I cannot see the shared folder that was set-up within the counterpart user account in the PC with XP Home. How do I set it up so the "limited" user account on the PC with XP Pro can access the counterpart shared folder on the other PC?