I created a form with a name field in it, made it the extended name, saved the form. came back to it a while later, open the name field to change it to "simple" instead, but that dropdown is disabled. Basically any time I go back to a name field it is disabled. The same issue occurs across different forms and sites, so I would rule out other plugins interfering.
Only seen in latest version of chrome, but I haven't tried other browsers. Here's a screenshot that illustrates it with the inspector showing the disabled tag in the select: http://jkudi.sh/fWD6oS
Not a big deal for me personally since I know how to easily un-disable the field, but others may find this annoying so I thought I'd bring it up.
Cheers