openwrt не работает cron

#!/bin/sh

PATH=/sbin:/bin:/usr/sbin:/usr/bin

sleep 30
sh /etc/init.d/cron enable
sh /etc/init.d/cron start 
0-59 * * * * sh /bin/update_dundns.sh 2>/home/log/log.cron &  # /dev/null
0-59 * * * * echo "`cat /bin/root`" >>/home/log/log.cron
 

sleep 7m
sh /usr/lib/ddns/dynamic_dns_updater.sh myddns

/bin/update_dundns.sh: line 2: 
: not found
sleep: invalid number '7m
'