Hi TerSans & welcome to SF
You may just need to check the permissions that are set on the server.
I had exactly the same thing happen to me trying to connect to an XP machine. The username & password i supplied was correct but it kept rejecting them because I hadn't got permission from XP to access it.
I suggest looking at the ACL of your server drive, adding NETWORK and assigning the appropriate permissions.
I hope this helps somewhat.