Problema com o cron no Ubuntu 7.04.

Os scripts dentro das pastas: /etc/cron.hourly, /etc/cron.daily, /etc/cron.weekly, /etc/cron.monthly não estão rodando.
Meu /etc/crontab é esse:

root@Servidor:~# crontab -l
# Minuto | Hora | Dia | Mês | Dia da Semana
# Semana: 0 = domingo 1 = seguda, assim vai...
01 * * * * root run-parts /etc/cron.hourly
02 8 * * * root run-parts /etc/cron.daily
22 8 * * 5 root run-parts /etc/cron.weekly
42 8 1 * * root run-parts /etc/cron.monthly
50 17 * * * root chown -R confor.confor /master/mult/
52 17 * * * root chmod -R 0770 /master/mult/
59 17 * * * root sh /usr/local/bin/limpar-squid.sh
14 08 * * * root apt-get update
20 08 * * * root apt-get -y upgrade
57 16 * * 5 root sh /usr/local/bin/limpar-squid.sh
58 16 * * 5 root chown -R confor.confor /master/mult/
59 16 * * 5 root chmod -R 0770 /master/mult/
15 12 * * * root sh /usr/local/bin/copy-proxy.sh
50 17 * * * root sh /usr/local/bin/limpar-samba.sh
50 16 * * 5 root sh /usr/local/bin/limpar-samba.sh
33 12 * * * root updatedb
25 08 * * * root chown -R claudio.estoque Estoque/
27 08 * * * root chmod -R 0770 Estoque/
15 08 * * * root sh /usr/local/bin/backup.sh
05 08 * * * root sh /usr/local/bin/mult_back.sh
05 18 * * * root sh /usr/local/bin/mult_back.sh
05 17 * * 5 root sh /usr/local/bin/mult_back.sh
04 08 * * * root sh /usr/local/bin/reset-mult.sh
00 18 * * * root /etc/init.d/gdm start
01 08 * * * root /etc/init.d/ssh start
57 18 * * * root /etc/init.d/ssh stop
59 17 * * 5 root /etc/init.d/ssh stop
40 10 * * * root echo "Cron OK" > /root/Cron.OK

Os comandos digitados diretamente no crontab funcionam normalmente.