HP Scanners and Snow Leopard - Solution
I had exactly the same problem so emailed HP. They replied with instructions which I could post here, if you like, but in a nutshell you need to go to applications and HP and click on Uninstaller and do it. Then go to HP support site and you will find a place to enter your all in one product number, and then you can download the updated software. You will need to reinstall your printer once you have installed the software and you will find that it all works again, brilliantly.