the nagios user is created - at least on Debian - by installing the package for nrpe. It shoudn't matter, in which user context the npcd-daemon runs, as long it can read the perfdata files.

But the directory for the perfdata files is empty, so there is nothing to read. That's the problem of qdtim and me. Maybe someone can tell us, where the perfdata files are located?

(My second problem is still, that I cannot reach any web site for PNP. Strange thing.)