The problem you are running into is a security issue. How are you accessing the drive via windows explorer? Is it the EXACT path you are typing into the map network drive box?
Have you tried using
net use x: \\path
in dos? If this completes successfully then your issue is with how you are mapping it. If it does not it is a security issue. Just because you can browse to it from the local machine via \\127.0.0.1\share does not meant it is working properly.
Get back to us and give us some more details and I would love to help you further.