Fedora :: KDE Print Manager In F15 - Printer May Not Be Connected

I have a rather ancient HP LaserJet printer that was working fine in fedora 14, but when I upgraded to Fedora 15, I can no longer get this printer to work. The printer's front panel reads "LaserJet 5P", but when I print out a test page, it's a "LaserJet 5MP". The printer is connected to my computer's parallel port, and it's capable of understanding PostScript, and I usually don't have any problems printing to it under various operating systems.

The following error comes and goes under the KDE print manager:
"Printer 'LaserJet_5P' may not be connected."
CUPS reports the following printer state:
"Processing - Printer not connected; will retry in 30 seconds..."

I have double-checked that my printer is indeed powered on and connected. And the following lines appear in the error log:
W [29/May/2011:18:03:02 -0700] no access to /System/Library/ColorSync/Profiles/sRGB Profile.icc
W [29/May/2011:18:03:02 -0700] no access to /System/Library/ColorSync/Profiles/sRGB Profile.icc
W [29/May/2011:18:03:02 -0700] no access to /System/Library/ColorSync/Profiles/Generic CMYK Profile.icc
W [29/May/2011:18:03:02 -0700] failed to CreateProfile: org.freedesktop.ColorManager.Failed:profile object path '/org/freedesktop/ColorManager/profiles/LaserJet_5P_Gray__' already exists .....

The first three warnings are regarding file paths that one would expect in an Apple OSX system. The "bad request" error is troublesome, because it indicates that either my browser or some configuration software on my system is sending garbage to CUPS. The last two errors occurred when I tried to use the KDE print configuration tool, which was not smart enough to ask me for the root password, which CUPS needs. By the way, the device URI is "parallel:/dev/lp0". Is this still the correct URI?