How to fix HP C6150 scanner issue after upgrading to Mac OS X 10.5.4

I don’t exactly remember what broke the scanner functionality of my two-year old HP C6150 fax/scanner/printer. It could be the Mac OS X 10.5.4 update, or it could be the HP Printer Driver 1.1 update. When i tried to use the scanner, i get the following error message:

Scanner could not be initialized

To fix this, just uninstall the Hewlett-Packard software using the provided HP Uninstaller.app. HP support provided a solution, but it is not necessary – actually, not possible to – install just the scanner software first. Just reinstall the whole package and this problem will go away.