A while ago (March or maybe February) the AJAX stopped working on my Gravity Forms. I assumed I had changed something, the theme or plugin, and that it had caused the problem but I didn't get around to investigating until now. I found the conflict pretty easily. It is with the Simple Taxonomies plugin by yoast.
As this plugin hasn't been updated since 2009 logic tells me that it was a change at Gravity Forms that caused the conflict.
Can anyone help me?