Can you run "hp-check" at the CLI as root?
I'm sorry to be so ignorant, but I don't know what the CLI is.

But I did run "hp-check" as root in a terminal.
[root@localhost ~]# hp-check
HP Linux Imaging and Printing System (ver. 3.12.9)
Dependency/Version Check Utility ver. 15
Copyright (c) 2001-14 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).
Check types:
a. EXTERNALDEP - External Dependencies
b. GENERALDEP - General Dependencies (required both at compile and run time)
c. COMPILEDEP - Compile time Dependencies
d. [All are run-time checks]
PYEXT SCANCONF QUEUES PERMISSION
Status Types:
OK
MISSING - Missing Dependency or Permission or Plug-in
INCOMPAT - Incompatible dependency-version or Plugin-version
Saving output in log file: /root/hp-check.log
Initializing. Please wait...
warning: pclinuxos-2012 version is not supported. Using pclinuxos-2009.0 versions dependencies to verify and install...
---------------
| SYSTEM INFO |
---------------
Kernel: 3.2.18-pclos2.bfs #1 SMP PREEMPT Thu May 24 04:44:50 CEST 2012 GNU/Linux
Host: localhost.localdomain
Proc: 3.2.18-pclos2.bfs #1 SMP PREEMPT Thu May 24 04:44:50 CEST 2012 GNU/Linux
Distribution: pclinuxos 2012
-----------------------
| HPLIP CONFIGURATION |
-----------------------
HPLIP-Version: HPLIP 3.12.9
HPLIP-Home: /usr/share/hplip
warning: HPLIP-Installation: Auto installation is not supported for pclinuxos distro 2012 version
Current contents of '/etc/hp/hplip.conf' file:
# hplip.conf. Generated from hplip.conf.in by configure.
[hplip]
version=3.12.9
[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.12.9
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
libusb01-build=no
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=3.12.9
restricted-build=no
ui-toolkit=qt4
qt3=no
qt4=yes
policy-kit=no
hpijs-only-build=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:
warning: Could not access file: No such file or directory
<Package-name> <Package-Desc> <Required/Optional> <Min-Version> <Installed-Version> <Status> <Comment>
--------------------------
| External Dependencies |
--------------------------
gs Ghostscript REQUIRED 7.05 9.02 OK -
network Network-wget OPTIONAL - 1.14 OK -
error: dbus DBus REQUIRED - 1.4.16 MISSING 'DBUS may not be installed or not running'
scanimage Shell-Scanning OPTIONAL 1.0 1.0.22 OK -
policykit Admin-Policy-framework OPTIONAL - 0.102 OK -
xsane SANE-GUI OPTIONAL 0.9 0.998 OK -
error: cups CUPS REQUIRED 1.1 - INCOMPAT 'CUPS may not be installed or not running'
-------------------------
| General Dependencies |
-------------------------
reportlab Python-PDF-Lib OPTIONAL 2.0 2.1 OK -
error: libcrypto OpenSSL-Crypto-Lib REQUIRED - 1.0.0 MISSING 'libcrypto needs to be installed'
pil Python-Image-Lib OPTIONAL - 1.1.7 OK -
pyqt4-dbus PyQt4-DBUS REQUIRED 4.0 4.9.4 OK -
error: libjpeg JPEG-Lib REQUIRED - - MISSING 'libjpeg needs to be installed'
libpthread POSIX-Threads-Lib REQUIRED - 2.13 OK -
python-dbus Python-DBUS REQUIRED 0.80.0 0.83.2 OK -
error: cups-ddk CUPS-DDK OPTIONAL - - MISSING 'cups-ddk needs to be installed'
python-devel Python-SDK REQUIRED 2.2 2.6.6 OK -
pyqt4 Python-Qt4 REQUIRED 4.0 4.9.4 OK -
error: cups-devel CUPS-SDK REQUIRED - - MISSING 'cups-devel needs to be installed'
error: sane-devel SANE-SDK REQUIRED - - MISSING 'sane-devel needs to be installed'
error: libusb USB-Lib REQUIRED - 1.0 MISSING 'libusb needs to be installed'
sane Scan-Lib REQUIRED - - OK -
error: cups-image CUPS-Image-Lib REQUIRED - - MISSING 'cups-image needs to be installed'
error: libnetsnmp-devel SNMP-Networking-SDK REQUIRED 5.0.9 - MISSING 'libnetsnmp-devel needs to be installed'
python-xml Python-XML-Lib REQUIRED - 2.0.1 OK -
python-notify Desktop-notifications OPTIONAL - - OK -
------------------------------
| Compile Time Dependencies |
------------------------------
error: gcc gcc-Compiler REQUIRED - 4.5.2 MISSING 'gcc needs to be installed'
error: libtool Build-tools REQUIRED - - MISSING 'libtool needs to be installed'
make GNU-Build-tools REQUIRED 3.0 3.81 OK -
----------------------
| Python Extentions |
----------------------
cupsext CUPS-Extension REQUIRED - 3.12.9 OK -
pcardext PhotoCard-Extension REQUIRED - 3.12.9 OK -
hpmudext IO-Extension REQUIRED - 3.12.9 OK -
-----------------------
| Scan Configuration |
-----------------------
error: hpaio HPLIP-SANE-Backend REQUIRED - 3.12.9 MISSING 'hpaio not found in /etc/sane.d/dll.conf. hpaio needs to be added in this file.'
scanext Scan-SANE-Extension REQUIRED - 3.12.9 OK -
------------------------------
| DISCOVERED SCANNER DEVICES |
------------------------------
device `v4l:/dev/video0' is a Noname USB Camera (046d:08af) virtual device
--------------------------
| DISCOVERED USB DEVICES |
--------------------------
No devices found.
---------------------------------
| INSTALLED CUPS PRINTER QUEUES |
---------------------------------
EPSON_Epson_Stylus_NX510
------------------------
Type: Unknown
Device URI: ///dev/null
HP-DeskJet-722C
---------------
Type: Unknown
Device URI: socket://HP:9100
PPD: /etc/cups/ppd/HP-DeskJet-722C.ppd
PPD Description: HP DeskJet 722C Foomatic/pnm2ppa
Printer status: printer HP-DeskJet-722C disabled since Fri 05 Oct 2012 05:22:33 PM EDT - Unable to locate printer 'HP'!
warning: Printer is not HPLIP installed. Printers must use the hp: or hpfax: CUPS backend for HP-Devices.
HP_Officejet_4500_G510g_m
-------------------------
Type: Unknown
Device URI: ///dev/null
--------------
| PERMISSION |
--------------
error: groups user-groups Required - - MISSING ['lp']
-----------
| SUMMARY |
-----------
Missing Required Dependencies
-----------------------------
error: 'libdbus-1_3-devel' package is missing/incompatible
error: 'libcups2' package is missing/incompatible
error: 'openssl' package is missing/incompatible
error: 'libjpeg62-devel' package is missing/incompatible
error: 'libcups2-devel' package is missing/incompatible
error: 'libsane1-devel' package is missing/incompatible
error: 'libusb-devel' package is missing/incompatible
error: 'libcups2-devel' package is missing/incompatible
error: 'libnet-snmp10-devel' package is missing/incompatible
error: 'gcc-c++' package is missing/incompatible
error: 'libtool' package is missing/incompatible
error: 'hpaio' package is missing/incompatible
Missing Optional Dependencies
-----------------------------
error: 'cups-ddk' package is missing/incompatible
Total Errors: 15
Total Warnings: 1
Re-run 'hp-check --fix' command to prompt and fix the issues.
Done.
[root@localhost ~]#
That's a lot of stuff!!

Do I now need to run "hp-check --fix"?