Desktop locks up when early "open window" msgbox i

Knop5.01:
While using qtparted to format a usb flash drive,
hotplug (udev?) popup offered to open window (usb folder)
after clicking ok, I noticed that qtparted was only 33% done formatting it.
The desktop became totally unresponsive (open progs still worked ok)
(After qtparted finished) I had to ctrl-alt-backspace out of Xwin and do a shutdown.
(the usb drives were fine on reboot)

Is there an easy way to restart KDE without rebooting?
(xsession gave wallpaper, no desktop. Do I need to kill KDE first?)
Thanks.