UPDATE: I finally figured out that nagios was having trouble detecting the plugins. Correcting the nagios.cfg file to point to the right location for the plugins solved the problem. (just in case anyone else has a similar problem).
This is my first attempt at using Nagios...basically, I have it monitoring a few hosts and simply checking if they are alive, and checking a few to see if apache is ok.
My problem is that I am getting alert notifications that the host is down, when it is not - it may be a clue that these are being sent apparently every eight hours, and not getting alerts when I ought to be in some cases. I was hoping for some pointers as to where to start troubleshooting when you have false host down reports (easing the threshold for reporting escalations, increasing tolerance on ping tests, etc?).
I am using version 1.2 (stable) on slackware 9.1. If there is any futher information, like specific configuration files you would like me to post, please let me know.