Update adaptive form jcr:title dynamically

Hi

I have an adaptive form whereby we would like to update the field titles (jcr:title) dynamically (as in at initialise time). I have attached a simple piece of javascript to the initialisation expression

this.setAttribute("Some other title for this field", "jcr:title")

This works brilliantly for a GuideTextBox and when the form is rendered it shows the field title change but it doesn't work for a GuideRadioButton.

Does anyone have any thoughts on why this would be or maybe a better way on achieving this kind of functionality?