This is a general symptom of high load or very slow I/O. The Recent Visitors record file stores both the current information and the historical numbers. If it becomes corrupt, it's automatically discarded.
I noticed that you've set the cutoff to 300 minutes. That's ten times the default, and possibly one of the reasons for the problem. Cut it down to 60 minutes instead.
![[Linked Image from navaho.infopop.cc]](http://navaho.infopop.cc/progress.gif)
