check_log help please

Hi everyone, I’m relatively new to nagios after foolishly suggesting it as an alternative to
HP openview that my company currently uses. A daft move as I now have been charged
with setting up a system for evaluation.
I have configured most of the systems ok and have nrpe working however I am having some
issues with the check_log plugin, it is now reporting
Status Information: Log check error: Log file -O does not exist!
It was working, so I am pretty confused!
The definition on the client nrpe.cfg is
#Matts check_log definition
command[check_log]=/usr/lib/nagios/plugins/check_log -F $ARG1$ -O $ARG2$ -q $ARG3$
and at the server end

check_log command definition

define command{
command_name check_log
command_line $USER1$/check_log -F /var/log/messages -O /var/tmp/check_log_messages -q “yum”
}
When run on the command line it works fine.
Can anyone shed any light on this or suggest where to look?

Thankyou
Matt