HOSTS Manipulation and NetBIOS Sharing

[SnapDive]

I have a machine that is a domain member. I am in the local
Administrators group. Windows Server 2003. A Share called "MyShare" at
c:\myshare has share permissions: everyone:F , administrators:F ,
system:F. On another machine, I have a HOSTS entry called "locsvr"
because the full name of the server is "nyc1102app3".

From the remote machine, I can access the share at
\\nyc1102app3\myshare.

If I try to access it at \\locsvr\myshare I get this error:

You were not connected because a duplicate name exists on the network.
Go to System in Control Panel to change the computer name and try
again.

Why?!

Help!

Thanks.