processor at 100%

[squareyes]

Hi all,
it's been happening more often recently, something seems
to be taking over the processor. I run Gkrellm all the time,
and it is showing that the processor is running at 100%,
if I close everything, with only Gnome Desktop open,  it remains at 100%.
Mouse becomes very sluggish and jerky.
System monitor also shows it at 100%. Is there anyway I can find out
and kill the culprit.

System Monitor shows only Character applet, Gnome System monitor
running, Gam_server on and off at this moment.
Using 133.7 meg of 250 meg of ram
Using 128.9 meg of 729.5 of swap.

After a full shutdown/reboot,  it returns to normal.
thanks in advance.
Take Care
Winton