Parallel port scan fails for HP DeskJet 694c

The printer is connected to the parallel port and works just fine under CUPS using the cdj670 driver and URI parallel:/dev/lp0 . However, hp-setup and hp-makeuri fail to detect it's presence.

Versions:
Kernel = 2.6.24-gentoo-r8
HP Linux Imaging and Printing System (ver. 2.8.7)
Device URI Creation Utility ver. 4.4

ix ~ # whoami
root
ix ~ # hp-makeuri -c /dev/parport0
warning: hp-makeuri should not be run as root.
error: Device not found
ix ~ #hp-makeuri -c /dev/lp0
warning: hp-makeuri should not be run as root.
error: Device not found
ix ~ #ls -l /dev/lp0
crw-rw---- 1 root lp 6, 0 Feb 17 17:03 /dev/lp0
ix ~ #cat /proc/sys/dev/parport/parport0/autoprobe*
CLASS:PRINTER;
MODEL:DESKJET 690C;
MANUFACTURER:HEWLETT-PACKARD;
DESCRIPTION:Hewlett-Packard DeskJet 690C;
COMMAND SET:MLC,PCL,PML;