No information in some graphs

I'm running the latest professional version on a Windows 2003 server with SP1.

I'm checking approx 30 rules, and get them all to alert on each status change, and have been getting the notifications. I'm also getting each rule to graph it's results.



The problem is that some of the rules have no data showing in the graphs, even though they have been sending the alert notifications.



I've checked on it multiple times through the day, to see if anythings changed, but no avail. This is happening on a daily basis for specific rules. Most others are running & reporting fine.



Anything I should be looking at?

If the rules are not executed within the interval defined under the ADMIN section (graph) refresh rate then the values are considered missed and a blank point are plotted.



You may verify the content of the RRD database following the RRD manual that can be found here:

http://people.ee.ethz.ch/~oetiker/webtools/rrdtool/doc/index.en.html

Thanks, I've changed the refresh rate and it seems more reliable with the data now.