I upgraded one of my ThinkPads from Linux Mint 7 to Linux Mint 9 today, and discovered that I was no longer able to use my HP P1006 printer. The HP printer tool (hp-toolbox) detected the printer correctly, downloaded the appropriate plugin, but then couldn’t install the plugin. Running the tool from the command line didn’t give any extra information. This is a known bug in Ubuntu 10.04.
The solution is to download and build the HP printer package (known as hplip) from source. The complete instructions are here. I had to install the following extra packages before the configure and make steps would succeed: libjpeg-dev, libsnmp-dev, libcups2-dev, libusb-dev, python-dev, libsane-dev, and libcupsimage2-dev.