I know this has been visited many, many times - because I've found many of the threads and followed the instructions therein.
I've read every thread I can about the visual editor not working.
However, I am only having trouble using the Visual Editor on Mac OSX 10.8.
I initially thought this was due to Apple uninstalling JRE, but I reinstalled it and tested it on the Java site. I also read that Java Script is not the same as Java.
That being said, On my Mac Book Pro running Mountain Lion, Safari, Firefox or Chrome (all latest versions), I have only the HTML editor with all of the buttons. Everything works properly.
Everything with TinyMCE behaves normally on my iPad.
I've done everything listed in other threads - deleting and reloading wordpress-admin and wordpress-includes, clearing the caches, etc. That has not helped.
An indication that I have that might help is that although FireBug shows no errors, the FireFox error console shows a long string of errors all of which follow the same pattern: "Warning: error in parsing value for 'background-image'. Declaration Dropped.
My user profile has the "Turn off visual editor" item unchecked and that works - I tested it with my iPad.
Any assistance would be greatly appreciated.