HP Photosmart 5520 OS X 10.5.8 driver
I had the same issue with a HP Photosmart 5520 install diskette requiring (the 64bit architecture) Mountain Lion, Lion, etc.  You can start the install with the install diskette, it will soon just finish as a 5520 with NO Functionality. While an older version photosmart driver is the best bet, be sure it has a wireless functionality (e.g older Photosmarts C4400 etc. did not work) You will need a WIRELESS supporting driver, viz the D100 driver. The D100 driver wireless access not only lets the Mactook running Leopard but as well an iBook running Tiger and a 3rd Gen iPod touch work excellently.  The color printing is better than I need. It copies and does what I generally need. 

I use the HP 5520 in STANDALONE mode to provide printing service for all devices in wireless access.

To be sure here must be some functionality I do not get, given all the adverts about all the "wonderful" nuances in the product.  But most all straight forward printing and copying functionality I need for my iPod iOS4, MacBook Leopard and iBook G3 on Tiger, work excellently; they can see it as either a D100 or as a 5520.