Nagios stops scheduling checks randomly!

From time to time around three times a month nagios stoppes scheduling checks for some random services on random servers. And in our company this represents huge problem…
Anyone has any ide how to fix this problem (I am running 3.0.1 version of nagios)?

First i’d update to the latest stable which is 3.0.6.

Are you sure it stops randomly and doesn’t depend on something else failing?
i had a nagios install once which “needed” to be restarted once a week as i never got to find what made it fail… but that was one fo the first 2.x versions…

I have upgraded to 3.0.6 version… I hope this works.