I have a Kernel task using, well currently around 75% of a core on my 2008MP and it seems to use much less, when I am not running anything. But say for example, I encode video and/or use folding at home. The Kernel Task uses more and more cpu. If i run nothing, the task uses virtually no CPU. Two other things in activity monitor that i can link to the Kernel task are not responding. they are. "usereventagent" and "coreadiod" They all stay with restart and shutdown. and with all apps closed. any ideas?