Hi, I had the same problem and got this from another post. Just substitute the HP 1215 software wherever it says 7350. It worked for me!
Here is the method I pulled from a few different sources:
1) Unplug printer
2) Download the latest HP Photosmart 7350 package (ver 2.5.6 as of 05/04/06) from:
http://h10025.www1.hp.com/ewfrf/wc/softwareList?lc=en&cc=us&lang=en&product=7288 6&dlc=en&os=219
3) Set Print Setup Utility to "Open Using Rosetta"
3.1) Go to MacHD\Applications\Utilities\Printer Setup Utility and "Get Info"
3.2) Check the "Open Using Rosetta" box
3.3) Close the window
4) Run the HP Uninstaller (in MacHD\Applications\HP)
5) Delete the Library\Printers\HP directory
6) Restart
7) Run HP Installer from above
7.1) Select Photosmart 7350
7.2) Perform Easy Install
7.3) Launch HP Setup Assistant when prompted
8) Plug in printer when prompted by HP Setup Assistant and hit "Next"
10) Launch Printer Setup Utility
11) Select your HP Photosmart 7350 and *ignore the other drop-downs*
12) At the bottom of the Printer Setup Utility, click on "More Printers"
13) Select hp photosmart in the top drop-down
14) Select your printer and click "Add"