If I use System Monitor to monitor more than one occurrence of "Kernel: Processor Usage," the second and following occurrences of "Kernel: Processor Usage" show 100 percent processor usage. Why is that so?

If I use System Monitor to monitor more than one occurrence of "Kernel: Processor Usage," the second and following occurrences of "Kernel: Processor Usage" show 100 percent processor usage. Why is that so?
or
Why does the processor usage rate always fluctuate between 20% and 60% even when no application is running, and when I operate the mouse, the usage rate would drop suddenly?

* This symptom still occurs even I have set the CPU rate to [Full] on [PowerPanel].

Microsoft has confirmed the symptom and is now investigating its cause.

We have checked the symptom but have no information on the details of the problem. Please kindly contact Microsoft technical support for more information.

Article ID: Q178563
Title: System Monitor Shows 100 Percent for Kernel Processor Usage Item.
Link: http://support.microsoft.com/support/kb/articles/Q178/5/63.asp