Nagios and samhain

I have nagios setup with nrpe. I am having a problem installing the samhain file system integrity check running. la-samhna.de/samhain/manual/nagios.html . That page seems to ingore nrpe entirely. Anyway when i run

./check_nrpe -H $ip-address -c check_samhain

I get

NRPE: Command ‘check_samhain’ not defined

from both the machine with nagios and nrpe. I have defined check_samhain in checkcommands.cfg and nrpe.cfg ( out of desperation really ) but that doesnt seem to solve the problem. I should also point out that samhain is only installed on the machine that runs nrpe. Other commands like check_load work without a problem. The check_samhain script is on both machines. ( Putting it in the nagios machine didnt help ) Could somone point me to what am doing wrong. Ty
Edited ]