NIS 2010 shows inconsistent CPU history graph in "1d" (one day) format

The pix below pretty much tell the story.  I looked at the CPU history recently and pix #1 showed a long segment of "computer off".  That's not the actual history.  I closed the NIS window, then later opened it up again and looked at the CPU history again, and it showed the correct, actual CPU history (pix #2).  Bug? 

 

And I subsequently was able to reproduce the anomaly, but not consistently.  You may have to close it and open it up again a number of times before the CPU history changes. 

 

NIS1.jpg

 

 

 

NIS2.jpg