Thanks for clarifying that Erza. I had been editing the file, restarting the box and then telnet'd in but used the 'unencryptsetup' command which I'm guessing sets the crontab to the default 1,31 1-6 * * * and so on irrespective of what I had already done to the 'root' file.
All up and running now and kindly borrowed some code from another thread and have now got it set up to run every 5 mins in order to clear the backlog which should be done now I've had it on for 24hrs!
Thanks for the help/advice Erza