G'day Zeki,
A few ideas.
When windows connects to a SMB share it will try to auto authenticate, so sometimes you get the connection authenticated with anonymous etc, which does not have permission to connect to the actual share. Windows will only allow one username/password per session to the SMB server.

So the fix is on the windows box, issues a "net use /delete" to all of the connections to that SMB server, and then do a specific "net use \\\172.16.0.2\file-depo /user:yourname" from a cmd prompt.
Or reboot your windows box.


Rgds Ben.