The call setFocus on a TextInput in a form will not work unless the user has clicked on the movie. This means I have no way to set the default TextInput when the movie first loads. I?ve tried calling setFocus from within the onLoad method of the form and I have also tried calling it from a method run by an interval. Is this a bug?

You should use:

Selection.setFocus("instanceName")

instanceName is your text field instance name.