[Plug-in: Frontend Builder] – Not working with WP 3.6.1

This is my first post here, so please let me know if I’ve not followed the forum rules correctly.

I’ve installed Frontend Builder about a month ago. It never worked perfectly, but I could finagle it into working for me.

I updated to 3.6.1 a few days ago, and although my clients site is still working fine, I can’t access the Frontend Builder editor. I’m using Maya Theme.

Screenshots/Examples:
My installation.
There example page.

I’ve deactivated several plug-ins, and spent the last few days looking for the conflict with no success.

Any help of suggestions would be greatly appreciated.