modified script from here http://wiki.dropbox.com/TipsAndTricks/TextBasedLinuxInstall/UbuntuStartup

dropbox

#!/bin/sh
### BEGIN INIT INFO
# Provides:          dropbox
# Required-Start:    $local_fs $remote_fs $network $syslog $named
# Required-Stop:     $local_fs $remote_fs $network $syslog $named
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# X-Interactive:     false
# Short-Description: dropbox service
### END INIT INFO


# dropbox service
#DROPBOX_USERS="user1 user2"

DROPBOX_GROUP=dropbox
IFS=,
DROPBOX_USERS=$(getent group "${DROPBOX_GROUP}" | cut -d: -f4)

DAEMON=.dropbox-dist/dropbox

start() {
    echo "Starting dropbox..."
    for dbuser in $DROPBOX_USERS; do
        HOMEDIR=$(getent passwd $dbuser | cut -d: -f6)
        if [ -x "${HOMEDIR}"/"${DAEMON}" ]; then
            HOME="$HOMEDIR" start-stop-daemon -b -o -c $dbuser -S -u $dbuser -x "${HOMEDIR}"/"${DAEMON}"
        fi
    done
}

stop() {
    echo "Stopping dropbox..."
    for dbuser in $DROPBOX_USERS; do
        HOMEDIR=$(getent passwd $dbuser | cut -d: -f6)
        if [ -x "${HOMEDIR}"/"${DAEMON}" ]; then
            start-stop-daemon -o -c $dbuser -K -u $dbuser -x "${HOMEDIR}"/"${DAEMON}"
        fi
    done
}

status() {
    for dbuser in $DROPBOX_USERS; do
        dbpid=$(pgrep -u $dbuser dropbox)
        if [ -z $dbpid ] ; then
            echo "dropboxd for USER $dbuser: not running."
        else
            echo "dropboxd for USER $dbuser: running (pid $dbpid)"
        fi
    done
}

case "$1" in

    start)
        start
        ;;

    stop)
        stop
        ;;

    restart|reload|force-reload)
        stop
        start
        ;;

    status)
        status
        ;;

    *)
        echo "Usage: /etc/init.d/dropbox {start|stop|reload|force-reload|restart|status}"
        exit 1

esac

exit 0

Pertect, install and working from dropbox 3.10.7 -
change only line
DAEMON=.dropbox-dist/dropboxd (with end 'd')