My installation on OS X contains in ~/username/Library/Arduino only one file 'preferences.txt' which, as I noted, is overwritted with each startup.
The system Library /Library/Application/Support contains no Arduino folder.
/Library/Preferences contains no Arduino folder
~/Library/PreferencePanes contains no Arduino folder
~/Library/Preferences does contain a cc.arduino.Arduino.plist file
From the command line there is no /lib folder. Nor is there a lib folder in /sbin or /bin.
So I guess my lack of familiarity with the underlying OS is my problem. And still only a very hard to read light gray text on a bright white background in the IDE.
Thanks for you response however.