Description of problem:
system-config-printer no longer sees USB printer

Version-Release number of selected component (if applicable):
system-config-printer-0.7.74.10-3.fc8

How reproducible:
Always

Steps to Reproduce:
1.Start with 32 bit PC with almost all packages installed, all updates current,
and SELinux turned off.
2.Start system-config-printer with USB printer plugged in.
3.Click on "New Printer".
  
Actual results:
No USB printers are shown

Expected results:
The USB printer shown should show up

Additional info:

dmesg shows:
usblp0: USB Bidirectional printer dev 2 if 0 alt 0 proto 2 vid 0x043D pid 0x0070
usbcore: registered new interface driver usblp

lsusb (which sees the printer) gives:
Bus 001 Device 001: ID 0000:0000  
Bus 005 Device 001: ID 0000:0000  
Bus 004 Device 001: ID 0000:0000  
Bus 003 Device 002: ID 043d:0070 Lexmark International, Inc. 
Bus 003 Device 001: ID 0000:0000  
Bus 002 Device 001: ID 0000:0000  

hp-probe -busb gives:
warning: No devices found on the 'usb' bus. If this isn't the result you are
expecting,
warning: check to make sure your devices are properly connected and powered on.

Everything was working properly until a few weeks ago.  I have tried backing out
to installation CD rpm's for system-config-printer, udev, cups, cups-libs, but
the problem still persists.  I have also tried booting to a previous kernel, but
that also did nothing to fix this problem.  I suspect that the problem may be
due to an rpm other than system-config-printer, but I have no idea which rpm
that would be.