desktop 2050 J510 scanner not found

1. Your Linux Distribution and version: Ubuntu 10.04 lucid lynx with kernel 2.6.32-25-generic-pae
2. Your printer make/model: Deskjet 2050 J510
3. If possible, run 'hp-check -t' and post the output.

HP Linux Imaging and Printing System (ver. 3.10.9)
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 tka 2.6.32-25-generic-pae #44-Ubuntu SMP Fri Sep 17 21:57:48 UTC 2010 i686 GNU/Linux

Distribution:
ubuntu 10.04

Checking Python version...
OK, version 2.6.5 installed

Checking PyQt 4.x version...
OK, version 4.7.2 installed.

Checking for CUPS...
Status: scheduler is running
Version: 1.4.3
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 3.10.9 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=3.10.9

[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.10.9
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=no
gui-build=yes
scanner-build=yes
fax-build=yes
dbus-build=yes
cups11-build=no
doc-build=yes
shadow-build=no
hpijs-install=no
foomatic-drv-install=no
foomatic-ppd-install=no
foomatic-rip-hplip-install=no
hpcups-install=yes
cups-drv-install=yes
cups-ppd-install=no
internal-tag=3.10.9.11
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:
[installation]
version = 3.10.9.11
date_time = 10/19/2010 09:15:23

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

  Device URI Model
  -------------------------------- ---------------------------
  hp:/usb/Deskjet_2050_J510_series HP Deskjet 2050 J510 series
  ?serial=CN04R12HWT05D1

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

Deskjet_2050_J510
-----------------
Type: Printer
Device URI: hp:/usb/Deskjet_2050_J510_series?serial=CN04R12HWT05D1
PPD: /etc/cups/ppd/Deskjet_2050_J510.ppd
PPD Description: HP Deskjet 2050 j510 Series, hpcups 3.10.9
Printer status: printer Deskjet_2050_J510 is idle. enabled since Tue 19 Oct 2010 09:15:04 AM CST

HP Linux Imaging and Printing System (ver. 3.10.9)
System Tray Status Service ver. 2.0

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.

/usr/lib/pymodules/python2.6/gtk-2.0/gtk/__init__.py:127: RuntimeWarning: PyOS_InputHook is not available for interactive use of PyGTK
  set_interactive(1)
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'...

No scanners were identified. If you were expecting something different,
check that the scanner is plugged in, turned on and detected by the
sane-find-scanner tool (if appropriate). Please read the documentation
which came with this software (README, FAQ, manpages).

---------------------
| 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 0x8711 at 001:006:
    Device URI: hp:/usb/Deskjet_2050_J510_series?serial=CN04R12HWT05D1
    Device node: /dev/bus/usb/001/006
    Mode: 0664

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

elqanah adm lp dialout fax cdrom floppy tape audio dip video plugdev fuse lpadmin netdev admin sambashare vboxusers

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

No errors or warnings.

Done.

4. A detailed explanation of your problem.
Scanner not found.
- xsane states: "no devices available"
- simple scan states: "no scanners detected"

5. Steps to recreate the problem.