phranque - 11:10 pm on Oct 8, 2008 (gmt 0) have you looked at the value of the error codes returned by the commands.
normally the output of a cron script is mailed to the owner of the cron process (root?) or the user specified in the MAILTO environment variable.
perhaps the commands sent some output you haven't seen?
if you have problems seeing the emailed output, you could try redirecting standard error and output to a file that you can examine after cron runs.
the special variable $? contains the return code of the last commmand...
have you looked at the value of the error codes returned by the commands.