If you had read what the posts on that forum said you'd see that the smart web printing feature has been retired and replaced by the HP Bing Toolbar's Smart Print functionality. However this doesn't work for IE9 either.
So I stand by my original post; I think you are out of luck.
just downloaded IE9 and HP Smart Web Printing no longer works, tried to download the smart print with the bing toolbar, it downloaded then disapeared, also the ADD ons , when I check them to enable them it disabled them and now cannot enable them again.
I do not feel that we are beggers as this product worked with IE 8 and Microsoft pushed it on us and HP saw fit not to upgrade it's product that we have all been using for a long time. We pay for this software when we buy there product at inflated prices so the least they can do is upgrade there products aswell.