[CentOS] Script not running correctly as cronjob

Hi

I have a script to resign all DNS zones every two weeks. When i run the script from bash, it works like it should. But when it is executed in cron not. Its starting normal as cronjob:
Feb  1 03:00:01 xxx CROND[20116]: (root) CMD (sh /opt/dnssec/resign_dnssec_zones.sh)

But after i get a mail that everything is finsihed, but it isn't.
03:04:28 DNSSEC-Signierung abgeschlossen

The script deletes the old signed zones, but don't resign it. The mail is also sent.
Below the script.

Anybody an idea why it doesn't work in cron?^
I cannot find any error in any log.

Best regards
Daniel


#!/bin/bash
KSKDIR="/etc/named/KSK"
ZSKDIR="/etc/named/ZSK"
ZONEDIR="/var/named/chroot/var/named"
LOG="/var/named/chroot/var/log/dnssec_resign.log"
MAILREC="monitor at xx"

#delete old signed files
rm -rf $ZONEDIR/*.signed

#delete the old log
rm -rf $LOG

#read the zonefiles
ZONEFILES=$(ls -p $ZONEDIR | grep -v '/$' | grep -v 'dsset*')

for FILES in $ZONEFILES; do
#remove the .zone at the end
        ZONE=$(echo "${FILES%.*}")

#remove the old signed zone
    rm -rf $ZONEDIR/$ZONE.signed

#Sign the zone
        cd $ZONEDIR
        dnssec-signzone -o $ZONE -k $KSKDIR/K$ZONE.*.key -e +3024000 -f $ZONE.signed $ZONEDIR/$ZONE.zone $ZSKDIR/K$ZONE.*.key >> $LOG

#Set the correct permissions
        chown named.named $ZONEDIR/*.signed
        chmod 755 $ZONEDIR/*.signed
        sleep 5
done
rm -rf $ZONEDIR/named.zone

echo $(date +"%T")"DNSSEC-Signierung abgeschlossen - Neustart des Servers" >> $LOG
echo "$(cat $LOG)" | mail -s "DNSSEC-Signierung abgeschlossen auf xxx" $MAILREC