Kernel, python issue

For the past week my processor has been running at 100% almost nonstop. Activity Monitor tells me that python and kernel_task are using anywhere from 39-42% (each) of the processor queue at any time. This just started happening without any major change in my habits, software, etc - is this normal? Has anyone else experienced the same thing?

iMac G5 iSight
OS X 10.4.9
PowerPC 970 1.9 Ghz

OK, I figured out one thing - this only seems to happen when Mail is downloading a new voicemail from Vonage.

In addition, I've found that my option-cmd-j shortcut doesn't work for erasing junk mail, nor does the menu command. I have to delete each message.

So it looks as though Mail might be the problem. Is there a way to reinstall Mail, or update the installation?

You could uninstall Mail and then reinstall it using your OS X disc and Pacifist.

I was just about to do that when I noticed that ALL my mail messages were all taking a little longer than usual to download and route. I remembered that I have JunkMatcher installed and that it does its business with Python. I uninstalled it, and all seems to be well now.

So if you have JunkMatcher and your processor starts to spend a lot of its time running Python, try disabling the JunkMatcher rules in Mail. If that doesn't work, uninstall JunkMatcher. No need to reinstall Mail.