[Nagiosplug-help] popen problems

[Volcane]

hey there,

I'm busy installing nagios on FreeBSD 5.4, versions:
nagios-2.0.b3_1
nagios-plugins-1.4_3,1

which corresponds to original tar files:
nagios-2.0b3.tar.gz
nagios-plugins-1.4.tar.gz

Whenever I try to run some of the check_* commands I get something similar:
/usr/local/libexec/nagios/check_ping -H localhost -w 4000,80% -c 5000,100%
CRITICAL - You need more args!!!
Could not open pipe:

At first I thought the plugin is to blame but a bit of picking through
the source have me believe that lines 126 to 129 of popen.c is what is
really causing my nightmares:

                if (i >= argc - 2) {
                        printf (_("CRITICAL - You need more args!!!\n"));
                        return (NULL);
                }

Does anyone have any advise?