Weight and sorting reset when uploading via ajax

Around line 487 in the filefield_js() function:

The second time a form_builder() function is used the resulting $form is stripped of previous weights added to its elements via processing functions. This basically causes the fields inside the updated widget to change places right after uploading. I assume the form_builder function returns the form this way because the $form array submitted to it lacks any weights thus assuming there's no need to sort it. Only an assumption. I'm sure its not that important considering that not too many people want to switch around the fields inside a widget , but I thought you'd like to know.

Thanks a lot for the great module!