Cannot print at all (Canon S400 + CUPS)

[Peter S Galbraith <p.galbraith@globetrotter.net>]

This is the first time ever that I have difficulty printing on
Linux.  Weird.

Bootup reports:
 parport0: PC-style at 0x378 (0x778) [SPP,ECP,ECPEPP,ECPPS2]
 parport0: detected irq 7; use procfs to enable interrupt-driven operation.
 parport_probe: succeeded
 parport0: Printer, Canon S400
 lp0: using parport0 (polling).

Yet, nothing happens if I even cat a file to /dev/lp0 :

 $ cat logo.gri > /dev/lp0

I have the following packages installed for CUPS:

$ dpkg -l | grep cups
ii  cupsomatic-ppd 0.20010420-3   cups printer ppd's from LinuxPrinting.org
ii  cupsys         1.1.10-2       Common UNIX Printing System(tm) - server
ii  cupsys-client  1.1.10-2       Common UNIX Printing System(tm) - client pro
ii  cupsys-pstoras 1.1.10-2       Common UNIX Printing System(tm) - pstoraster
ii  libcupsys2     1.1.10-2       Common UNIX Printing System(tm) - libs

If I try to print a plain ASCII file using CUPS, I get an error
in /var/log/cups/error_log

$ lp logo.gri

 I  Job 12 queued on 'Canon' by 'root'.
 I  Started filter /usr/lib/cups/filter/pstops (PID 525) for job 12.
 I  Started filter /usr/lib/cups/filter/cupsomatic (PID 526) for job 12.
 I  Started backend /usr/lib/cups/backend/parallel (PID 527) for job 12.
 E  PID 526 stopped with status 32!

This is using the ppd file I got from linuxprinting.org, stored
as /usr/share/cups/model/canonS400.ppd and setup using lpadmin.
The listing in http://localhost:631/printers looks okay to me:

 Canon BJC-3000, Foomatic + s400a1.upp
 Description:
 Location:
 Printer State: idle, accepting jobs.
 Device URI: parallel:/dev/lp0

Any clues?
What is error status 32?

Thanks,
Peter