I've solved this issue, sorta: Gedit has a working spell-checker for PCLOS, and Gedit has proved to be just about as handy as Kate. This doesn't affect the problems I've had in Tomboy or Kmail, but I can type stuff in Gedit first if I want to be sure of the spelling.
Gee whizzz! A KDE problem solved by using Gnome! Not good! However, PCLOS 2010 with KDE 4 doesn't have the problem: No Kate!! Is that intentional?
In faith, Dave