Yesterday I installed the latest version of the Hewlett Packard printer driver package and I'm glad that I did. The new printer driver fixed a problem that I have had with my HP Deskjet D4160. I had been forced to power cycle the printer between print jobs. For some reason if I sent two separate print jobs to the printer the second one would cause the printer to get into a weird unrecoverable state where it would just blink two of the indicator lights. Now that I've installed v2.7.7 of HPLIP that problem is fixed.
http://hplip.sourceforge.net/
Even though this is on Source Forge it is the official HP driver developed by HP.
Naturally if your HP printer works now then don't "fix" it.
I had one problem with the installer. It stripped the secondary groups from my normal user accounts and replaced whatever was there with the lp group. If you use secondary group membership extensively, as I do, then you will have to fix your user accounts after you run the installer.