unable to specify media folder on upload

After playing with this I've come to the conclusion this relates to having multiple file types to choose from. I'm not entirely sure which modules can't handle this properly, but if I disable any custom file types we have (there is one), the initial media folder selection works.... still have the same problem with changing the media folder from within the wysiwyg 'add media' dialog, but I'm pretty sure that's been like that for a while now.

When there are multiple file types available and the file_entity setting for "Skip filetype selection" is set, the file type defaults to 'undefined' and never shows the field form.

Because of this, when the hook_file_presave fires, the field_folder isn't in the format the function is expecting. I ended up fixing this in a custom module by unsetting the file_presave hook and creating my own which is pretty much identical except with extra checks around finding the tid.

/**
 * Implementats hook_module_implements_alter()
 * Ensure the hook for media_browser_plus_file_presave is unset
 *
 */
function media_browser_plus_helper_module_implements_alter(&$implementations, $hook) {
  // see if media_browser_plus's hook for presaving the file exists
 if ($hook == 'file_presave' && isset($implementations['media_browser_plus'])){
    // if so unset it so we can replace with our own version
    unset($implementations['media_browser_plus']);
  }
}

/**
 * Implememnts hook_field_attach_presave()
 * Media browser plus has problems when multiple file types are present.
 * Same as media_browser_plus_file_presave but has extra checks for finding tid
 */
function media_browser_plus_helper_file_presave($entity) {
  // the tid is not where we expect it
  if (empty($entity->field_folder[LANGUAGE_NONE][0]['tid'])) {
    // we don't even have the field_folder - set to root
    if (empty($entity->field_folder[LANGUAGE_NONE])) {
      $root = media_browser_plus_get_media_root_folder();
      $entity->field_folder[LANGUAGE_NONE] = array(array('tid' => $root->tid));
    }
    // weird case with multiple file types, set up the field_folder right
    else {
      $tid = $entity->field_folder[LANGUAGE_NONE];
      $entity->field_folder[LANGUAGE_NONE] = array(array('tid' => $tid));
    }
  }

  // Ensure file is stored in the appropriate folder.
  $folder = taxonomy_term_load($entity->field_folder[LANGUAGE_NONE][0]['tid']);
  $new_path = file_stream_wrapper_uri_normalize(file_uri_scheme($entity->uri) . '://' . media_browser_plus_construct_dir_path($folder) . '/' . basename($entity->uri));
  // Only move file if necessary.
  if ($entity->uri !== $new_path) {
    media_browser_plus_move_file($folder->tid, $entity, FILE_EXISTS_RENAME, FALSE);
  }
}