Since upgrading to Ubuntu 11.10 my printer - an HP deskjet F300 series - will no longer print from any word processor, including gedit. The scanner still functions and I can print emails. It was working correctly with TextMaker, LibreOffice and Gedit before the upgrade
I had the same problem with my Deskjet d2660. The solution was to download and install the latest drivers directly from the HP site.
The download dialog may tell you that Ubuntu already has the correct driver for your printer, nevertheless, download and install it anyway.