[Nagiosplug-help] collectd-nagios error "Connecting to daemon"

[Jarrod]

Hi,

I'm posting to ask for help with a little problem using
collectd-nagios plugin. If this isn't the right place, please ignore.

I've setup a command called check_collectd in my commands.cfg for
nagios using the following config:

define command{
      command_name    check_collectd
      command_line    /usr/bin/collectd-nagios -s
/var/run/collectd-unixsock -n $ARG1$ -H $ARG2$ -d $ARG3$ -w $ARG4$ -c
$ARG5$
      }

I then setup a service check as follows:

define service {
      check_command                check_collectd!load/load!za!longterm!1!100
      host_name                         host.domain.com
      use                                     generic-service
      service_description            LOAD
}

This should work. And when I run the /usr/bin/collectd-nagios command
string from above (with relevant substitutions) as the nagios user, it
works! Why, then, would I get the error "ERROR: Connecting to daemon
at /var/run/collectd-unixsock failed." from nagios?

Please help if you have any experience with this plugin?

Thanks in advance.

Jarrod