I have run into the problem of usb devices locking up KDE processes and making accessing Konqueror for file management in Mandrake 10.1 unusable. The problem revolves around the kde service KDED Mount Watcher.

If you go to the Kmenu->System->Configuration->KDE->Components->Service Manager
One item listed is the KDED Mount Watcher.

I went into KDE System Guard and killed two instances of kded. Then I went back into KDE Service Manager. It now says "Unable to contact KDED!". However I don't notice any performance problems. But now when I plug in my usb device I can again access Konqueror and my Home directory. So the problem lies somewhere with KDED, permissions probably since none of this is an issue when logging into KDE as root. I'm going to do more tests and post more on the Mandrakeusers.org Board.