Comment 1 for bug 64425

Snip from init script in gutsy:

case "$1" in
        start)
                log_daemon_msg "Starting the Winbind daemon" "winbind"

                mkdir -p /var/run/samba/winbindd_privileged || return 1
                chgrp winbindd_priv $PIDDIR/winbindd_privileged/ || return 1
                chmod 0750 $PIDDIR/winbindd_privileged/ || return 1
                start-stop-daemon --start --quiet --oknodo --exec $DAEMON -- $WINBINDD_OPTS

                log_end_msg $?
                ;;

Does that solve the problem? Instead of proxy, we are using winbindd_priv group. On setting up, you should just add proxy user to winbindd_priv group.