It shouldn't have simply displayed the files in the past, unless their was no security applied to it. When browsing samba shares and prompted for logins, when I had it set up it needed the domain and username in the form of:
and then the password. It depends what your domain separator is as defined in your smb.conf. It might be '+' or '\', but so long as that user has permissions on the WIndows share, you should gain access to the files.
