check_eximailqueue problem

Hello

I’m having great difficulty trying to put check_eximailqueue to work.

I’v sucessfully instaled nagios and all other basic plugins work fine, but my virtual ubuntu 11 machine, being monitored and used exacly to test the plugin, gives me “Mailqueue WARNING - query returned no output!”

The monitoring machine runs debian lenny.

The author of the plugin warns that it may happen if the nagios user is not in the exim group. The only exim user I found in /etc/group where Debian-exim, and I added nagios to it. It did not work.

I can manually run a check from the lenny machine:
#/usr/lib/nagios/plugins/check_nrpe -H ubuntumachine -c check_eximailqueue
Mailqueue OK - 0 messages on queue

And locally in the ubuntu machine:
#/usr/lib/nagios/plugins/check_eximailqueue -w 100 -c 400
Mailqueue OK - 0 messages on queue

But it doesn’t work in the nagios interface.

I’m sorry if my post lack any information, I would appreciate any help.