10-11pm RRD gap in graphs (4.1.1)

I have an odd issue...

From around 10pm at night to around 11pm (EST) I have a gap in my CPU and Processes/Users graphs.

I haven't seen any reasons in the hobbit logs. Other RRD graphs are fine (disk, vmstat, etc)

This is not just one night, but every night. I am using the hobbit client on the hobbit server, and hobbit client on another linux box (both are CentOS 4).

Has anyone else seen this? What is significant about CPU, Proc/Users graphs?

Thanks

Craig Cook

Systems Monitoring Consulting and Support Services http://www.cookitservices.com