Wow. Like, double WOW.
Let me make this simple for you: on foreign language keyboard layouts (I have a Portuguese Layout on a standard Apple Portuguese keyboard, but apparently this happens for other languages as well) every time I press a key an error message is appended to /var/log/windowserver.log:
... Sep 10 20:44:18  kCGErrorNoneAvailable: CGXKeyEventTranslate: key translation failure Sep 10 20:44:18  kCGErrorNoneAvailable: CGXKeyEventTranslate: key translation failure Sep 10 20:44:18  kCGErrorNoneAvailable: CGXKeyEventTranslate: key translation failure ...
No wonder my iBook's battery life under Tiger is only a fraction of what I had under Panther - it's not the hardware, it's the absolutely idiotic fact that everything I type results in a hard disk write.
I'm linking my log file to /dev/null and hoping it will stick across reboots. Er... no, I'm not. I'm now looking through discussions for a definitive fix.
At this point, I'm looking for something that does not require enabling and disabling the root user, as per this message - that's a bit too dumb for my liking, and doesn't allow me to understand what the actual problem is.
Someone please file this in Radar for me, I'm too disgusted right now.
Update: The root trick worked on my iBook. I will be trying to figure out what this actually does to the system, though.