OK so my situation is not the same (my system doesn't crash only the mount command freezes) Anyway, maybe this is a workaround for your problem: try to mount using cifs instead of smbfs (see man mount.cifs for any possible small diferences in options).
-- mount -t smbfs works from cmdline https://launchpad.net/bugs/47685 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs