Date Picker Don't work!

Hi, I have a problem with Date Picker.

I have created a field of type Date Picker, name of field “data_evento” http://img35.imageshack.us/img35/5237/0t8d.jpg

But when i write a new post it’s impossibile f0r me select a data, the field it’s a simple text filed (look attachment _data_picker_in_post).
http://img11.imageshack.us/img11/6624/6zcn.jpg

Please help me 🙂

Thanks, Ale.

http://wordpress.org/plugins/advanced-custom-fields/