you will need to uninstall iRite before installing CSS Form Builder 2.
Perhaps a good idea to update the message and documentation everywere that the old version of Html editor is called iRite. I used a lot of time checking the forums about the HTML Editor error i was getting trying to install Form Build 2.
error i got was:
it seems you may have installed CSS Form Builder while still having HTML EDitor installed.
removing iRite and reinstalling Form Builder 2 solved the problem.
I hope this helps other people as well.
Ruben