Thanks for your help, Jason. And also to Ray who followed up.
Just as an fyi to anyone else who may have this, the problem was related to a Spry validation on the textarea. Apparently when adding the HTML editor to a textarea with validation, it changes things and causes some kind of javascript loop so it can't proceed as normal.
I'm probably doing a horrible job of explaining it but the bottom line is after removing the Spry validation language for the textarea (looks something like: var Comments_Spry = new Spry.Widget.ValidationTextarea("Comments_Spry");) the form works just fine.
Thanks again to you both for great WA support.