Can't print on HP all-in-one.

Running Fedora 16 with linux version 3.1.5-6, hplip-3.11.10, and an HP Officejet 5510 All-in-one. Running hp-check yields the following:

HP Linux Imaging and Printing System (ver. 3.11.10)
Dependency/Version Check Utility ver. 14.3

Copyright (c) 2001-9 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Note: hp-check can be run in three modes:
1. Compile-time check mode (-c or --compile): Use this mode before compiling the
HPLIP supplied tarball (.tar.gz or .run) to determine if the proper dependencies
are installed to successfully compile HPLIP.
2. Run-time check mode (-r or --run): Use this mode to determine if a distro
supplied package (.deb, .rpm, etc) or an already built HPLIP supplied tarball
has the proper dependencies installed to successfully run.
3. Both compile- and run-time check mode (-b or --both) (Default): This mode
will check both of the above cases (both compile- and run-time dependencies).

Saving output in log file: hp-check.log

Initializing. Please wait...

---------------
| SYSTEM INFO |
---------------

Basic system information:
Linux familyroom.localdomain 3.1.5-6.fc16.i686.PAE #1 SMP Thu Dec 15 16:19:31 UTC 2011 i686 i686 i386 GNU/Linux

Distribution:
fedora 16

Checking Python version...
OK, version 2.7.2 installed

Checking PyQt 4.x version...
OK, version 4.8.6 installed.

Checking for CUPS...
Status: scheduler is running
Version: 1.5.0
error_log is set to level: warn

Checking for dbus/python-dbus...
dbus daemon is running.
python-dbus version: 0.83.0

------------------------------------
| COMPILE AND RUNTIME DEPENDENCIES |
------------------------------------

note: To check for compile-time only dependencies, re-run hp-check with the -c parameter (ie, hp-check -c).
note: To check for run-time only dependencies, re-run hp-check with the -r parameter (ie, hp-check -r).

Checking for dependency: CUPS - Common Unix Printing System...
OK, found.

Checking for dependency: CUPS devel- Common Unix Printing System development files...
OK, found.

Checking for dependency: CUPS image - CUPS image development files...
OK, found.

Checking for dependency: DBus - Message bus system...
OK, found.

Checking for dependency: gcc - GNU Project C and C++ Compiler...
OK, found.

Checking for dependency: GhostScript - PostScript and PDF language interpreter and previewer...
OK, found.

Checking for dependency: libcrypto - OpenSSL cryptographic library...
OK, found.

Checking for dependency: libjpeg - JPEG library...
OK, found.

Checking for dependency: libnetsnmp-devel - SNMP networking library development files...
OK, found.

Checking for dependency: libpthread - POSIX threads library...
OK, found.

Checking for dependency: libtool - Library building support services...
OK, found.

Checking for dependency: libusb - USB library...
OK, found.

Checking for dependency: make - GNU make utility to maintain groups of programs...
OK, found.

Checking for dependency: PIL - Python Imaging Library (required for commandline scanning with hp-scan)...
OK, found.

Checking for dependency: PolicyKit - Administrative policy framework...
OK, found.

Checking for dependency: PyQt 4 DBus - DBus Support for PyQt4...
OK, found.

Checking for dependency: Python DBus - Python bindings for DBus...
OK, found.

Checking for dependency: Python devel - Python development files...
OK, found.

Checking for dependency: Python libnotify - Python bindings for the libnotify Desktop notifications...
OK, found.

Checking for dependency: Python XML libraries...
OK, found.

Checking for dependency: Python 2.3 or greater - Required for fax functionality...
OK, found.

Checking for dependency: Python 2.2 or greater - Python programming language...
OK, found.

Checking for dependency: Reportlab - PDF library for Python...
OK, found.

Checking for dependency: SANE - Scanning library...
OK, found.

Checking for dependency: SANE - Scanning library development files...
OK, found.

Checking for dependency: scanimage - Shell scanning program...
OK, found.

Checking for dependency: xsane - Graphical scanner frontend for SANE...
OK, found.

----------------------
| HPLIP INSTALLATION |
----------------------

Currently installed HPLIP version...
HPLIP 3.11.10 currently installed in '/usr/share/hplip'.

Current contents of '/etc/hp/hplip.conf' file:
# hplip.conf. Generated from hplip.conf.in by configure.

[hplip]
version=3.11.10

[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.11.10
icon=/usr/share/applications
cupsbackend=/usr/lib/cups/backend
cupsfilter=/usr/lib/cups/filter
drv=/usr/share/cups/drv/hp

# Following values are determined at configure time and cannot be changed.
[configure]
network-build=yes
pp-build=yes
gui-build=yes
scanner-build=yes
fax-build=yes
dbus-build=yes
cups11-build=no
doc-build=yes
shadow-build=no
hpijs-install=yes
foomatic-drv-install=yes
foomatic-ppd-install=no
foomatic-rip-hplip-install=no
hpcups-install=yes
cups-drv-install=yes
cups-ppd-install=no
internal-tag=3.11.10
restricted-build=no
ui-toolkit=qt4
qt3=no
qt4=yes
policy-kit=no
hpijs-only-build=no
lite-build=no
udev-acl-rules=yes
hpcups-only-build=no
hpijs-only-build=no

Current contents of '/var/lib/hp/hplip.state' file:
# hplip.state - HPLIP runtime persistent variables.

[plugin]
installed=0
eula=0

Current contents of '~/.hplip/hplip.conf' file:
[last_used]
printer_name = officejet-5500-series
working_dir = .
device_uri = "hp:/usb/officejet_5500_series?serial=MY4CDG11GP96"

[fax]
email_address = <email address hidden>
voice_phone = 814-692-4491

[installation]
version = 3.11.10
date_time = 12/28/2011 14:53:56

[settings]
systray_messages = 0
systray_visible = 0

[commands]
scan = /usr/bin/xsane -V %SANE_URI%

[refresh]
rate = 30
enable = false
type = 1

[polling]
enable = false
device_list =
interval = 5

--------------------------
| DISCOVERED USB DEVICES |
--------------------------

  Device URI Model
  -------------------------------- ------------------------
  hp:/usb/officejet_5500_series?se HP officejet 5500 series
  rial=MY4CDG11GP96

---------------------------------
| INSTALLED CUPS PRINTER QUEUES |
---------------------------------

Canon-iP1800-series
-------------------
Type: Unknown
Device URI: usb://Canon/iP1800%20series
PPD: /etc/cups/ppd/Canon-iP1800-series.ppd
PPD Description: Canon iP1800 series Ver.2.70
Printer status: printer Canon-iP1800-series is idle. enabled since Thu 22 Dec 2011 11:47:31 AM EST
warning: Printer is not HPLIP installed. Printers must use the hp: or hpfax: CUPS backend to function in HPLIP.

officejet-5500-series
---------------------
Type: Printer
Device URI: hp:/usb/officejet_5500_series?serial=MY4CDG11GP96
PPD: /etc/cups/ppd/officejet-5500-series.ppd
PPD Description: HP Officejet 5500 Series, hpcups 3.11.10
Printer status: printer officejet-5500-series disabled since Thu 22 Dec 2011 11:51:16 AMBackend /usr/lib/cups/backend/hp does not exist!
Communication status: Good

officejet_5500_fax
------------------
Type: Fax
Device URI: hpfax:/usb/officejet_5500_series?serial=MY4CDG11GP96
PPD: /etc/cups/ppd/officejet_5500_fax.ppd
PPD Description: HP Fax hpcups
Printer status: printer officejet_5500_fax is idle. enabled since Thu 22 Dec 2011 06:57:50 PM EST
Communication status: Good

----------------------
| SANE CONFIGURATION |
----------------------

'hpaio' in '/etc/sane.d/dll.conf'...
OK, found. SANE backend 'hpaio' is properly set up.

Checking output of 'scanimage -L'...
device `v4l:/dev/video0' is a Noname Camera virtual device
device `hpaio:/usb/officejet_5500_series?serial=MY4CDG11GP96' is a Hewlett-Packard officejet_5500_series all-in-one

---------------------
| PYTHON EXTENSIONS |
---------------------

Checking 'cupsext' CUPS extension...
OK, found.

Checking 'pcardext' Photocard extension...
OK, found.

Checking 'hpmudext' I/O extension...
OK, found.

Checking 'scanext' SANE scanning extension...
OK, found.

-----------------
| USB I/O SETUP |
-----------------

Checking for permissions of USB attached printers...

HP Device 0x3a11 at 001:004:
    Device URI: hp:/usb/officejet_5500_series?serial=MY4CDG11GP96
    Device node: /dev/bus/usb/001/004
    Mode: 0664
getfacl: Removing leading '/' from absolute path names
# file: dev/bus/usb/001/004
# owner: root
# group: lp
user::rw-
user:rich:rw-
group::rw-
mask::rw-
other::r--

---------------
| USER GROUPS |
---------------

rich

-----------
| SUMMARY |
-----------

error: 1 error or warning.

Note under INSTALLED CUPS PRINTER QUEUES the line
Printer status: printer officejet-5500-series disabled since Thu 22 Dec 2011 11:51:16 AMBackend /usr/lib/cups/backend/hp does not exist!

But the hp file is in the backend directory, and I have reset the permissions to be owner (instead of root). Also note that scanning works properly on the HP and I can print properly on the Canon printer not connected to HPLIP.

How can I get HPLIP to recognize the cups backend file?