It seems caused by windows live sign-in assistant. I had exact same problem.
http://social.technet.microsoft.com/Forums/en/w7itpronetworking/thread/9c6f1d74-f7f0-4503 -94fa-0d79a5597527 -- samba client unable to access Windows 7 shares https://bugs.launchpad.net/bugs/458637 You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to samba in ubuntu. -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
