The same problem occurs for me.
The error Failed to load an application resource (internal error) appears when viewing preferences inside the application.
Like wise, when printing a similar error message is shown.
I have uninstalled the application, all adobe products on the system, removed application support files, preferences, PDF preferences and reinstalled. The problem still exists.
I installed the same version (v9.1.0) on another mac that had never had Acrobat installed before and the problem does not exist. I am able to view preferences and print.
Both are intel based Macs running 10.5.6.
Given that it works on one mac and not the other, what would be causing this?
Also is there an uninstall tool for Adobe Acrobat Mac from Adobe?