Okay, I am totally stumped. I have had this problem for months, tried various ways to get around it, finally have been using the default Gnome-based environment because nothing has helped: my keyboard stopped working in KDE.
I am using a yum updated FC5 version of Fedora. The keyboard _used_ to work, but stopped working right about the time I was fiddling with getting Korean input working with SCIM. Perhaps I changed a config file incorrectly? I don't know. I have tried everything except a fresh install of FC5...which I'm really not prepared to do, one because I no longer believe in the "if all else fails, reinstall" motto and two, because usually there are relatively simple answers and it's just better to solve them than reinstall. But boy, this really has me stumped.
The mouse works fine, I don't get any error messages as KDE starts (I just yum updated KDE to 3.5, thinking perhaps that would fix things, but it didn't), and the keyboard works in Gnome, Default, and Failsafe environments. Just not in KDE...and it _did_ work, fine, for about 2 years. I don't get any lights when I click Numlock or Scroll either. It's just like the keyboard isn't even plugged in.
I'm using a Dell Dimension 2400, FC5 184.108.40.206-1.2.fc5, KDE 3.5.5-1.1 (but it was on earlier versions too). Any and all help would be greatly appreciated. Thanks!