How do I disable ajax on file fields?
You can force the buttons to submit normally by unbinding the javascript events using something like this in a form alter:

// Disable ajax upload for file field
drupal_add_js("jQuery(function() { jQuery('#edit-field-image :submit').unbind(); });", 'inline');


It would be nice if there was a way to not have the javascript bound in the first place by manipulating the $form (or something else).