Use localhost:631 on firefox to install the printer, then as root go to /etc/sane.d, scroll down to dll.conf. Comment out any line that starts with hp. Add the string "hpaio" without the"".The Hp site says that the scanner is not supported but mine worked without doing any thing else. I don't know if this will work on other HP multifunction printers or not. I couldn't get it to install via hp-toolbox and the hp-toolbox still doesn't see it.
I hope this helps someone. I've been reading the forums for a week, trying every thing that looked like it might work. Sure feel's good when you
get a contrary piece of hardware to work.