Comment 17 for bug 1069898

I finally got it working, although apt complains. Andrea Rota does in fact give the solution above, though I missed it as well:

"if i downgrade this single package to libsane-hpaio_3.12.2-1ubuntu3.1_amd64 from Precise i can scan ok"

I found a copy of that file (here: http://packages.ubuntu.com/precise-updates/amd64/libsane-hpaio/download), but then ran into difficulties installing it. Synaptic or Apt either forced me to remove the other HP files (hplip and dependencies), or if I installed this file alone, they then insisted that this file be upgraded to the latest version - which was not the point. The answer, I eventually discovered, is to have hplip fully installed, THEN force the installation of this single .deb, using the command:

 sudo dpkg -i libsane-hpaio_3.12.2-1ubuntu3.1_amd64.deb

During the process you have to choose between keeping the later version or insist (correctly) on installing this apparently dodgy earlier one.

In fact, I did this after running the latest version of HPLIP (which I downloaded from here: http://hplipopensource.com/hplip-web/install/install/index.html). I'm not sure if I gained anything using this latest version (which probably only supports more printer models, rather than offering more features - though it does offer installation of fax facilities, which is not something I have had before), but do note that if you try it, it requires that an existing version of HPLIP be already installed. No idea why.