Perl scripts using Cron

[Thomas <tom@halahan.com>]

Hi,

I'm trying to automate a backup iso image using a perl 
script run as root.  The perl script works fine run as root 
from the command line, but fails when the exact same 
command is used in cron.

My root cron table looks like this:

30 17 * * 1-6 /usr/bin/perl /home/data/bin/full_backup.pl

I replaced this command with a simple echo that piped into 
a file which worked, so the timings are ok.

1)  Is there something I should be careful of when running 
perl via cron?  (I have not set the -w flag in the script.) 

2)  Where is the log file for cron, I simply cannot find it 
- I don't think there is one? 

Thanks,

Tom