Newbie question: Why aren't my cron jobs running?

[Walter Hurry]

As the subject says, this is probably a newbie question (I am new to 
FreeBSD but quite experienced at Linux).

FreeBSD9 on x86_64.

Cron is running:

$ ps -ax|grep cron

 1513  ??  Is     0:00.01 /usr/sbin/cron -s

 2283   0  S+     0:00.00 grep cron

$

I have a syntactically valid crontab:

$ crontab -l
#min hr dom month dow command

SHELL=/bin/bash

PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/home/
daddy/bin

HOME=/home/walterh

 00  02 *   *     *   /home/walterh/exports.sh

 05  02 *   *     *   /home/walterh/backup_etc.sh

 10  02 *   *     *   /home/walterh/systemcheck.sh

 15  02 *   *     *   /home/walterh/backup_bsd.sh

$ 

So what is wrong? Why is nothing happening? I have consulted the handbook 
but see nothing.