Help nagios and perl script



I have problems with nagios to perform plugin, I hope you could help me

I wrote few scripts in perl, I define a host and services, commands for each scripts but sometimes nagios refuse to perform my script.
It work fine randomly between 1 and 30 minutes and suddenly nagios refuse to perform one plugin. There is nothing in my log, everything allright except nothing happend.

I have and other error random too, this is the warning i got: