Help with duplicate ping problems


Nagios has been reporting a lot of duplicate pings lately. I did read about a bug in one of the versions of check_ping, but I checked my version and it is a version later than that of the one the bug reportedly affects. I’m wondering if I am monitoring too many hosts with this server an maybe it’s time for a new one. I am unable to find any documentation on how to determine if my server is overloaded. I also had another strange occurance this morning. We had a network device go down this morning, but we were not notified. I restarted the nagios service and then noticed these messages in the nagios event log prior to the restart for most of the hosts and services:

Informational Message[01-30-2009 09:13:18] Warning: The check of host ‘HE-VODSEM-42’ looks like it was orphaned (results never came back). I’m scheduling an immediate check of the host…

Also after the reboot I received a Nagios Total processes warning.

I currently have 201 hosts and 552 service checks.

I believe the server is an Intel Quad Core
model name : Intel® Xeon® CPU X3210 @ 2.13GHz
and if my memory serves me correctly I ordered the server with 4GB Ram

I should add the following things as well:
I monitor a good portion of our devices with SNMP.
I also run Cacti on this box to graph various devices including our network switches.

Any input or help would greatly be appreciated.