Be sure your print system in the KDE control panel is set to CUPS and not LPRNG. Also, in 9.1 LPRNG is the default print system. Probably the easiest way to make CUPS the default print system is to uninstall the LPRNG package and reinstall the CUPS package.
Also, a handy way to take advantage of CUPS printing in KDE is to use
kprinter --stdin
command in Mozilla, OpenOffice and other non-KDE programs. This gives you the printer selection dialog.
Again, check the KDE control panel to be sure that CUPS is the print system selected.