I am having the same issue with a HP 8600 Pro
Here is the output of my hp-check.log:
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hp-check[6552]: info: :
Initializing. Please wait...
LinuxMint
13
scheduler is running
1.5.3
Linux Gigabyte-i7 3.3.6-030306-generic #201205121335 SMP Sat May 12 17:36:12 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
hp-check[6552]: info: :
hp-check[6552]: info: :---------------
hp-check[6552]: info:

SYSTEM INFO |
hp-check[6552]: info: :---------------
hp-check[6552]: info: :
3.3.6-030306-generic #201205121335 SMP Sat May 12 17:36:12 UTC 2012 GNU/Linux
Gigabyte-i7
3.3.6-030306-generic #201205121335 SMP Sat May 12 17:36:12 UTC 2012 GNU/Linux
hp-check[6552]: info: : Kernel: 3.3.6-030306-generic #201205121335 SMP Sat May 12 17:36:12 UTC 2012 GNU/Linux
Host: Gigabyte-i7
Proc: 3.3.6-030306-generic #201205121335 SMP Sat May 12 17:36:12 UTC 2012 GNU/Linux
Distribution: linuxmint 13
hp-check[6552]: info: :
hp-check[6552]: info: :-----------------------
hp-check[6552]: info:

HPLIP CONFIGURATION |
hp-check[6552]: info: :-----------------------
hp-check[6552]: info: :
hp-check[6552]: info: :HPLIP-Version: HPLIP 3.12.6
hp-check[6552]: info: :HPLIP-Home: /usr/share/hplip
hp-check[6552]: info: :HPLIP-Installation: Auto installation is supported for linuxmint distro 13 version
hp-check[6552]: info: :
hp-check[6552]: info: :Current contents of '/etc/hp/hplip.conf' file:
hp-check[6552]: info: :# hplip.conf. Generated from hplip.conf.in by configure.
[hplip]
version=3.12.6
[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/ppd/HP
ppdbase=/usr/share/ppd
doc=/usr/share/doc/hplip-3.12.6
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=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=3.12.6
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
hp-check[6552]: info: :
hp-check[6552]: info: :Current contents of '/var/lib/hp/hplip.state' file:
hp-check[6552]: info:

lugins are not installed. Could not access file: No such file or directory
hp-check[6552]: info: :
hp-check[6552]: info: :Current contents of '~/.hplip/hplip.conf' file:
hp-check[6552]: info: :[upgrade]
notify_upgrade = true
last_upgraded_time = 1342828106
pending_upgrade_time = 0
latest_available_version = 3.12.6
[settings]
systray_visible = 0
systray_messages = 0
[last_used]
device_uri = "hp:/net/Officejet_Pro_8600?zc=HPC6AD96"
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 = 07/21/2012 19:49:47
version = 3.12.6
hp-check[6552]: info: : <Package-name> <Package-Desc> <Required/Optional> <Min-Version> <Installed-Version> <Status> <Comment>
hp-check[6552]: info: :
hp-check[6552]: info: :--------------------------
hp-check[6552]: info:

External Dependencies |
hp-check[6552]: info: :--------------------------
hp-check[6552]: info: :
hp-check[6552]: info: : gs Ghostscript REQUIRED 7.05 9.05 OK -
hp-check[6552]: info: : network Network-wget OPTIONAL - 1.13.4 OK -
hp-check[6552]: info: : dbus DBus REQUIRED - 1.4.18 OK -
hp-check[6552]: info: : scanimage Shell-Scanning OPTIONAL 1.0 1.0.22 OK -
hp-check[6552]: info: : policykit Admin-Policy-framework OPTIONAL - 0.104 OK -
hp-check[6552]: info: : xsane SANE-GUI OPTIONAL 0.9 0.998 OK -
scheduler is running
hp-check[6552]: info: : cups CUPS REQUIRED 1.1 1.5.3 OK 'CUPS Scheduler is running'
hp-check[6552]: info: :
hp-check[6552]: info: :-------------------------
hp-check[6552]: info:

General Dependencies |
hp-check[6552]: info: :-------------------------
hp-check[6552]: info: :
hp-check[6552]: info: : reportlab Python-PDF-Lib OPTIONAL 2.0 2.5 OK -
hp-check[6552]: info: : libcrypto OpenSSL-Crypto-Lib REQUIRED - 1.0.1 OK -
hp-check[6552]: info: : pil Python-Image-Lib OPTIONAL - 1.1.7 OK -
hp-check[6552]: info: : pyqt4-dbus PyQt4-DBUS REQUIRED 4.0 4.9.1 OK -
hp-check[6552]: info: : libjpeg JPEG-Lib REQUIRED - - OK -
hp-check[6552]: info: : libpthread POSIX-Threads-Lib REQUIRED - 2.15 OK -
hp-check[6552]: info: : python-dbus Python-DBUS REQUIRED 0.80.0 1.0.0 OK -
hp-check[6552]: info: : python-devel Python-SDK REQUIRED 2.2 2.7.3 OK -
hp-check[6552]: info: : pyqt4 Python-Qt4 REQUIRED 4.0 4.9.1 OK -
hp-check[6552]: info: : cups-devel CUPS-SDK REQUIRED - 1.5.3 OK -
hp-check[6552]: info: : sane-devel SANE-SDK REQUIRED - 1.0.22 OK -
hp-check[6552]: info: : libusb USB-Lib REQUIRED - 1.0 OK -
hp-check[6552]: info: : sane Scan-Lib REQUIRED - 1.0.22 OK -
hp-check[6552]: info: : cups-image CUPS-Image-Lib REQUIRED - 1.5.3 OK -
hp-check[6552]: info: : libnetsnmp-devel SNMP-Networking-SDK REQUIRED 5.0.9 5.4.3 OK -
hp-check[6552]: info: : python-xml Python-XML-Lib REQUIRED - 2.0.1 OK -
hp-check[6552]: info: : python-notify Desktop-notifications OPTIONAL - - OK -
hp-check[6552]: info: :
hp-check[6552]: info: :------------------------------
hp-check[6552]: info:

Compile Time Dependencies |
hp-check[6552]: info: :------------------------------
hp-check[6552]: info: :
hp-check[6552]: info: : gcc gcc-Compiler REQUIRED - 4.6.3 OK -
hp-check[6552]: info: : libtool Build-tools REQUIRED - 2.4.2 OK -
hp-check[6552]: info: : make GNU-Build-tools REQUIRED 3.0 3.81 OK -
hp-check[6552]: info: :
hp-check[6552]: info: :----------------------
hp-check[6552]: info:

Python Extentions |
hp-check[6552]: info: :----------------------
hp-check[6552]: info: :
hp-check[6552]: info: : cupsext CUPS-Extension REQUIRED - 3.12.6 OK -
hp-check[6552]: info: : pcardext PhotoCard-Extension REQUIRED - 3.12.6 OK -
hp-check[6552]: info: : hpmudext IO-Extension REQUIRED - 3.12.6 OK -
hp-check[6552]: info: :
hp-check[6552]: info: :-----------------------
hp-check[6552]: info:

Scan Configuration |
hp-check[6552]: info: :-----------------------
hp-check[6552]: info: :
hp-check[6552]: info: : hpaio HPLIP-SANE-Backend REQUIRED - 3.12.6 OK 'hpaio found in /etc/sane.d/dll.conf'
hp-check[6552]: info: : scanext Scan-SANE-Extension REQUIRED - 3.12.6 OK -
hp-check[6552]: info: :
hp-check[6552]: info: :------------------------------
hp-check[6552]: info:

DISCOVERED SCANNER DEVICES |
hp-check[6552]: info: :------------------------------
hp-check[6552]: info: :
hp-check[6552]: info: :No Scanner found.
hp-check[6552]: info: :
hp-check[6552]: info: :--------------------------
hp-check[6552]: info:

DISCOVERED USB DEVICES |
hp-check[6552]: info: :--------------------------
hp-check[6552]: info: :
hp-check[6552]: info: :No devices found.
hp-check[6552]: info: :
hp-check[6552]: info: :---------------------------------
hp-check[6552]: info:

INSTALLED CUPS PRINTER QUEUES |
hp-check[6552]: info: :---------------------------------
hp-check[6552]: info: :
hp-check[6552]: info: :
hp-check[6552]: info: :Officejet_Pro_8600
hp-check[6552]: info: :------------------
hp-check[6552]: info: :Type: Printer
hp-check[6552]: info:

evice URI: hp:/net/Officejet_Pro_8600?zc=HPC6AD96
hp-check[6552]: info:

PD: /etc/cups/ppd/Officejet_Pro_8600.ppd
hp-check[6552]: info:

PD Description: HP Officejet Pro 8600, hpcups 3.12.2
hp-check[6552]: info:

rinter status: printer Officejet_Pro_8600 is idle. enabled since Fri 20 Jul 2012 07:49:04 PM EDT
hp-check[6552]: info: :Communication status: Good
hp-check[6552]: info: :
hp-check[6552]: info: :
hp-check[6552]: info: :--------------
hp-check[6552]: info:

PERMISSION |
hp-check[6552]: info: :--------------
hp-check[6552]: info: :
stevep adm lp cdrom sudo dip plugdev scanner lpadmin sambashare vboxusers
hp-check[6552]: info: :groups user-groups Required - - OK stevep adm lp cdrom sudo dip plugdev scanner lpadmin sambashare vboxusers
hp-check[6552]: info: :
hp-check[6552]: info: :-----------
hp-check[6552]: info:

SUMMARY |
hp-check[6552]: info: :-----------
hp-check[6552]: info: :
hp-check[6552]: info: :Missing Required Dependencies
hp-check[6552]: info: :-----------------------------
hp-check[6552]: info: :None
hp-check[6552]: info: :
hp-check[6552]: info: :Missing Optional Dependencies
hp-check[6552]: info: :-----------------------------
hp-check[6552]: info: :None
hp-check[6552]: info: :
hp-check[6552]: info: :
hp-check[6552]: info: :Total Errors: 0
hp-check[6552]: info: :Total Warnings: 0
hp-check[6552]: info: :
hp-check[6552]: info: :No errors or warnings.
hp-check[6552]: info: :
hp-check[6552]: info:

one.
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Any suggestions please...