File Sharing for Windows Problem

Apologies or bothering you with a Windows issue, but I'm trying to setup file sharing from my 10.5 server for an XP Pro server. Now I have a system working fine, and I have a dedicated server using an IP that doesn't work. Here's the scoop:

10.5 Mac is setup beautifully with the SMB privileges, user names assigned, and folder specified identically.

Windows XP Pro machine needs to access the 10.5 Mac machine using an IP address due to the remote nature of the computer. It sees the computer, but fails to ever request a username / password, so it continues to report that I don't have "permission" to login.

Is there a trick to setting up an IP based Network Place that always asks for the username / password?

Consequently, it works perfect using the FTP protocol because it does ask for the username / password.

Thanks in advance for the help.