But that line was only added by the original installation... it wasn't actually within the installation.
I did the same thing as you (and went in deleted the original iRite folder, so that line was still on my page (as well as the new call to the HTMLeditor). The problem then becomes because that include no longer exists (cause I had deleted the folder with the old include).
So, for example, on your page where you placed the editor - just by deleting the old iRite editor out, it won't actually get rid of the old include that was placed at the top... you have to manually delete the old include line.
I hope what I am saying makes sense.