Problem:
In OS X Snow Leopard, you may experience problems accessing a SMB network share using either of the following methods:
Go > Network;
or, using Finder’s pane, under Shared;
.. and clicking ‘Connect As’ to log in.
You get the following error message:
You entered an invalid username or password. Please try again.
Workaround:
In Safari, type the following into the address bar:
smb://servername:139
Where servername is the server name of your SMB server.
Example:
smb://diskstation:139
a dialog box will appear, prompting you to log in. This should succeed and you will be prompted with a list of your devices shares. Selecting a share will mount it and display the contents.
Enjoy.