To OP and others: are you sure the problem is due to the credentials option? Check /var/log/kern.log. I tested with some of your options, and in kern.log I see:
> CIFS: Unknown mount option "auto" -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/995535 Title: .smbcredentials not working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/995535/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
