On Feisty scanning with HPLIP is pre-configured. On my 64-bit Feisty bpx there is "hpaio" in both /etc/sane.d/dll.conf and /etc/sane.d/dll.d/hplip. Most probably one is enough. There is no /etc/sane.d/hpaio.conf. Perhaps you need the /etc/sane.d/hpaio.conf as your device is a very new model and its USB IDs are not yet added to the current HPLIP driver.
On Feisty scanning with HPLIP is pre-configured. On my 64-bit Feisty bpx there is "hpaio" in both /etc/sane. d/dll.conf and /etc/sane. d/dll.d/ hplip. Most probably one is enough. There is no /etc/sane. d/hpaio. conf. Perhaps you need the /etc/sane. d/hpaio. conf as your device is a very new model and its USB IDs are not yet added to the current HPLIP driver.