HP LaserJet 4100N "Error: Unable to communicate with device"

Hi there,

My trusty, if rather old, HP LaserJet 4100N (with JetDirect card) mysteriously stopped working yesterday - I am not _aware_ of any changes being made to my environment.

The printer itself works insofar as I can print out the configuration page using the printer's on-board menu/buttons.
I can ping the device and web to the printer's IP address to configure it without any problems.

I updated HPLIP as previously I just had whatever version shipped with Ubuntu 12.04

I have tried "hp-setup -r" and removed the (only) printer followed by "hp-setup" and installed it again however it still fails to print.

hp-check yields the following:

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

 Kernel: 3.2.0-44-generic #69-Ubuntu SMP Thu May 16 18:27:54 UTC 2013 GNU/Linux
 Host: ubuntu2
 Proc: 3.2.0-44-generic #69-Ubuntu SMP Thu May 16 18:27:54 UTC 2013 GNU/Linux
 Distribution: ubuntu 12.04
 Bitness: 32 bit

-----------------------
| HPLIP CONFIGURATION |
-----------------------

HPLIP-Version: HPLIP 3.13.11
HPLIP-Home: /usr/share/hplip
HPLIP-Installation: Auto installation is supported for ubuntu distro 12.04 version

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

[hplip]
version=3.13.11

[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.13.11
html=/usr/share/doc/hplip-3.13.11
icon=/usr/share/applications
cupsbackend=/usr/lib/cups/backend
cupsfilter=/usr/lib/cups/filter
drv=/usr/share/cups/drv/hp
bin=/usr/bin

# Following values are determined at configure time and cannot be changed.
[configure]
network-build=yes
libusb01-build=no
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=3.13.11
restricted-build=no
ui-toolkit=qt4
qt3=no
qt4=yes
policy-kit=no
lite-build=no
udev-acl-rules=yes
udev_sysfs_rules=no
hpcups-only-build=no
hpijs-only-build=no

Current contents of '/var/lib/hp/hplip.state' file:
Plugins are not installed. Could not access file: No such file or directory

Current contents of '~/.hplip/hplip.conf' file:
[upgrade]
notify_upgrade = true
last_upgraded_time = 1386418461
pending_upgrade_time = 0
latest_available_version = 3.13.11

[settings]
systray_visible = 1
systray_messages = 0

[last_used]
device_uri = "hp:/net/HP_LaserJet_4100_Series?ip=192.168.1.100"
printer_name =
working_dir = .

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

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

[polling]
enable = false
interval = 5
device_list =

[fax]
voice_phone =
email_address =

[installation]
date_time = 08/12/13 21:39:36
version = 3.13.11

 <Package-name> <Package-Desc> <Required/Optional> <Min-Version> <Installed-Version> <Status> <Comment>

--------------------------
| External Dependencies |
--------------------------

 policykit Admin-Policy-framework OPTIONAL - 0.104 OK -
 gs Ghostscript REQUIRED 7.05 9.05 OK -
 network Network-wget OPTIONAL - 1.13.4 OK -
 scanimage Shell-Scanning OPTIONAL 1.0 1.0.22 OK -
 avahi-utils avahi-utils OPTIONAL - 0.6.30 OK -
 dbus DBus REQUIRED - 1.4.18 OK -
 cups CUPS REQUIRED 1.1 1.5.3 OK 'CUPS Scheduler is running'
 xsane SANE-GUI OPTIONAL 0.9 0.998 OK -

-------------------------
| General Dependencies |
-------------------------

 reportlab Python-PDF-Lib OPTIONAL 2.0 2.5 OK -
 libcrypto OpenSSL-Crypto-Lib REQUIRED - 1.0.1 OK -
 pil Python-Image-Lib OPTIONAL - 1.1.7 OK -
 pyqt4-dbus PyQt4-DBUS REQUIRED 4.0 4.9.1 OK -
 libjpeg JPEG-Lib REQUIRED - - OK -
 libpthread POSIX-Threads-Lib REQUIRED - 2.15 OK -
 python-dbus Python-DBUS REQUIRED 0.80.0 1.0.0 OK -
 python-devel Python-SDK REQUIRED 2.2 2.7.3 OK -
 pyqt4 Python-Qt4 REQUIRED 4.0 4.9.1 OK -
 cups-devel CUPS-SDK REQUIRED - 1.5.3 OK -
 sane-devel SANE-SDK REQUIRED - 1.0.22 OK -
 libusb USB-Lib REQUIRED - 1.0 OK -
 sane Scan-Lib REQUIRED - 1.0.22 OK -
 cups-image CUPS-Image-Lib REQUIRED - 1.5.3 OK -
 libnetsnmp-devel SNMP-Networking-SDK REQUIRED 5.0.9 5.4.3 OK -
 python-xml Python-XML-Lib REQUIRED - 2.0.1 OK -
 python-notify Desktop-notifications OPTIONAL - - OK -

------------------------------
| Compile Time Dependencies |
------------------------------

 gcc gcc-Compiler REQUIRED - 4.6.3 OK -
 libtool Build-tools REQUIRED - 2.4.2 OK -
 make GNU-Build-tools REQUIRED 3.0 3.81 OK -

----------------------
| Python Extentions |
----------------------

 cupsext CUPS-Extension REQUIRED - 3.13.11 OK -
 pcardext PhotoCard-Extension REQUIRED - 3.13.11 OK -
 hpmudext IO-Extension REQUIRED - 3.13.11 OK -

-----------------------
| Scan Configuration |
-----------------------

 hpaio HPLIP-SANE-Backend REQUIRED - 3.13.11 OK 'hpaio found in /etc/sane.d/dll.conf'
 scanext Scan-SANE-Extension REQUIRED - 3.13.11 OK -

------------------------------
| DISCOVERED SCANNER DEVICES |
------------------------------

No Scanner found.

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

No devices found.

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

HP_LaserJet_4100
----------------
Type: Printer
Device URI: hp:/net/HP_LaserJet_4100_Series?ip=192.168.1.100
PPD: /etc/cups/ppd/HP_LaserJet_4100.ppd
PPD Description: HP LaserJet 4100 Series v.3010.107 Postscript (recommended)
Printer status: printer HP_LaserJet_4100 is idle. enabled since Sun 08 Dec 2013 21:23:54 GMT
error: Unable to communicate with device (code=12): hp:/net/HP_LaserJet_4100_Series?ip=192.168.1.100
error: unable to open channel
error: Communication status: Failed

--------------
| PERMISSION |
--------------

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

Missing Required Dependencies
-----------------------------
None

Missing Optional Dependencies
-----------------------------
None

Total Errors: 1
Total Warnings: 0

Any assistance you can provide will be gratefully received as this is starting to drive me nuts!
Cheers,
Chris.