Can you run: sudo /etc/init.d/hplip status and post the output?
if hplip isn't running run sudo /etc/inid.d/hplip start also run lpstat -v and post that output as well. You may want to consider taking this to the hplip mailing list at http://hplip.sourceforge.net as this sounds more of how to than a ubuntu defect. and I will help you further from the hplip mailing list. Aaron HPLIP Team Member -- hplip cannot find DeskJet 5440 printer, despite CUPS's claims to the contrary https://launchpad.net/bugs/49107 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs