I'm dropping the Dynamic Dropdowns extension from the latest release in favor of using the WebAssist Framework builder Plug-ins and AJAX. It is possible to create the same effect with a cleaner and more modern code base this way. I'm still working on getting a tutorial put together to show people the concepts on how to get this done.
I could help you in a premier support ticket for now, and if you create a tutorial after based on what I show you then I would be willing to refund the cost.