There seems to be a jQuery conflict between Foobar notifications bar plugin (paid plugin) on the ACF field add/edit page, which makes the radio list inaccessible.
I looked into Foobar plugin JS code & found that they are calling a custom function on radio class "$('.radio').radio()", which screws up the radio list on ACF page.
ACF page: http://img255.imageshack.us/img255/6333/acfi.jpg
Foobar page: http://themergency.com/wp-content/uploads/2011/07/PerPageCustomization.jpg
I'll link them to this page, hopefully the conflict will be resolved by next version (of either plugin).
