I dunno what's in slack 9 as I've never ran it.
I've only ran 11 through 12.2.
Are you sure everything is up to date?
To me it sounds like you may not be adding everything you need.
The only time I've had a problem not being able to use my hp printer on any linux system is when I havn't met all my dependency needs.
You're printer also has to be turned on before it can be seen, no sarcasm intended but everyone has a duh moment.
I'm assuming you're still trying the hp printer.
Go through the dependencies list and double check yourself at this link:
http://hplipopensource.com/hplip-web...ros/other.html
A good many dependencies can be found at slacky.eu and installed with pkgtool if dependencies are the problem.
If slacky doesn't have them, they are assuredly in slackbuilds.
Not trying to sound condescending, but if you havn't figured out how to install from slackbuilds, say so.
It isn't a crime and I can point you to a dead simple tutorial that's easy to follow.
Once you have done that, download the hplip tarball from:
http://hplipopensource.com/hplip-web...slackware.html
The complete install instructions are there but it's as simple as ./configure, make, make install, reboot.
Just make sure the printer is turned on and connected before you even untar the tarball.
Before you reboot, chmod +x /etc/rc.d/rc.cups and cups will start on boot, every boot.
If cups isn't running you won't be able to configure your printer either.
After the reboot, find the hp device manager in your menu and run the setup from there or if you're one that likes to play in the terminal and running kde, you can kdesu hp-setup.
The above process takes me maybe an hour tops to do as the only thing I don't do or need is fax and all the dependencies are met, everything is up to date including foomatic and my printer/scanner works on the first try.
I also use the hp device manager for everything instead of the browser as it's simpler, at least for me.