Just a heads up in case it saves anyone else some headache. GravityForms + Shortcode Exec PHP causes a javascript error when you're creating / editing a form. The error is "object expected, edit_area_full" ... basically it's (Shortcode Excec PHP that is) looking for an instance of the WYSIWYG editor when one doesn't exist. Haven't gone into the Shortcode plugin code to look for a fix yet but I'll post again when I do.
Cheers.