If your system drive was set up with a case-sensitive HFS file system, HP's All-in-One installer will fail when it gets to the HP Setup Assistant -- it will ask you to "Select Device" and give you an empty list. To get the installer to work, you have to install it on a case-insensitive file system. I've confirmed this with version 7.9.1 of the PhotoSmart C6100 series and version 7.9 of the Officejet 7310 series drivers.
The solution? The only one I've found is to re-format and install on a file system that is not case sensitive. After hearing back from HP's tech support, they confirmed the problem and the solution:
Thank you for contacting HP Total Care.I only wish they had mentioned that anywhere in the online troubleshooting section. Sigh.
The software for the Photosmart C6180 is not supported on a case sensitive partition. You will have to install the drivers on a case-insensitive partition.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20070623004646642