How often do Sane update their listings. Is it a regular event or will I need to wait months?
This is not really a fault of Sane, this is a problem caused by HP, the guys at at Sane (who also work for nothing) have to reverse engineer the drivers because the companies do no realease the details of the drivers
When looking for a solution to your problem a came across a list of people who emailed HP and complained.
The more people who do that the better.
Or make sure next time you buy hardware, check it works in Linux, if not tell the company/shop why you are not buying it, they will eventually get message.