Users from Ubuntu NIS server cannot connect to DSS's shares.

In this case the common problem is encryption type of passwords. If you chose your NIS server to encrypt passwords with sha512 it won't work becouse DSS doesn't support this type of encryption. To fix this problem add "md5" to:  /etc/pam.d/common-password :

"password<------>[success=1 default=ignore]<---->pam_unix.so obscure sha512 md5" and recreate all users passwords.