I have tried the patch but it has a lot of problems. First, it is not able to put an icon into the tray. I get a "?" icon on one machine and no icon at all on another. Then it produces a lot of messages in the terminal from where I started "hp-systray" for testing. And if I quit via the "Quit" entry in the menu I get a segfault.

I use GNOME as the desktop, perhaps it works only on KDE desktops.

See all terminal output below.

till@till:~/ubuntu/hplip/svn/pkg-hpijs/hplip/build-area/hplip-3.10.2~rc1$ hp-systray

HP Linux Imaging and Printing System (ver. 3.10.2rc1)
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)
(8509) KStatusNotifierItemDBus::KStatusNotifierItemDBus: service is "org.freedesktop.StatusNotifierItem-8509-1"
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
(8509) KStatusNotifierItemPrivate::registerToDaemon: Registering a client interface to the KStatusNotifierWatcher
(8509) KStatusNotifierItemPrivate::registerToDaemon: KStatusNotifierWatcher not reachable
QSystemTrayIcon::setVisible: No Icon set
(8509) KToolInvocation::klauncher: klauncher not running... launching kdeinit
kdeinit4: preparing to launch /usr/lib/libkdeinit4_klauncher.so
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
klauncher(8519)/kio (KIOConnection) KIO::ConnectionServer::listenForRemote: Listening on  "local:/tmp/ksocket-till/klauncherMT8519.slave-socket"
kdeinit4: preparing to launch /usr/lib/libkdeinit4_kded4.so
kdeinit4: preparing to launch /usr/lib/libkdeinit4_kbuildsycoca4.so
klauncher(8519)/kio (KLauncher) KLauncher::processRequestReturn: "/usr/bin/kbuildsycoca4" (pid 8528) up and running.
kbuildsycoca4 running...
kbuildsycoca4(8528)/kdecore (KSycoca) KSycocaPrivate::openDatabase: Trying to open ksycoca from  "/var/tmp/kdecache-till/ksycoca4"
kbuildsycoca4(8528) KBuildSycoca::checkTimestamps: checking file timestamps
kbuildsycoca4(8528) KBuildSycoca::checkTimestamps: timestamps check ok
kbuildsycoca4(8528) kdemain: Emitting notifyDatabaseChanged ()
kded(8524)/kdecore (KSycoca) KSycocaPrivate::openDatabase: Trying to open ksycoca from  "/var/tmp/kdecache-till/ksycoca4"
klauncher(8519)/kdecore (KSycoca) KSycocaPrivate::openDatabase: Trying to open ksycoca from  "/var/tmp/kdecache-till/ksycoca4"
kdeinit4: preparing to launch /usr/lib/libkdeinit4_kconf_update.so
klauncher(8519)/kio (KLauncher) KLauncher::processRequestReturn: "kconf_update" (pid 8530) up and running.
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
klauncher(8519)/kdecore (KSycoca) KSycocaPrivate::openDatabase: Trying to open ksycoca from  "/var/tmp/kdecache-till/ksycoca4"
kdeinit4: preparing to launch /usr/bin/knotify4
klauncher(8519)/kio (KLauncher) KLauncher::processRequestReturn: "/usr/bin/knotify4" (pid 8531) up and running.
knotify(8532) NotifyByPopup::slotServiceOwnerChanged: "org.freedesktop.Notifications" "" "_"
Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
knotify(8532) KNotify::event: 1  ref= 0
QDBusConnection: name 'org.kde.knotify' had owner '' but we thought it was ':1.143'
Segmentation fault (core dumped)
till@till:~/ubuntu/hplip/svn/pkg-hpijs/hplip/build-area/hplip-3.10.2~rc1$