Drupal template files are not recognized
By default, the template file is expected to be in the same directory containing the module or the theme which defines the theme function. To use a different path, in the hook_theme() implementation you need to use the path property, which is defined as:


  
  path: Override the path of the file to be used. Ordinarily the module or theme path will be used, but if the file will not be in the default path, include it here. This path should be relative to the Drupal root directory.
  


So, in your case the code should be similar to the following one, since you are using a theme.

function dc_wiwo_theme($existing, $type, $theme, $path) {
  return array(
    'dc_wiwo_page' =&gt; array(
      'variables' =&gt; array('tweets' =&gt; array()),
      'path' =&gt; drupal_get_path('theme', 'dc_wiwo') . '/media';
      'template' =&gt; 'wiwo',
    ),
  );
}


For a module, the code would not be much different.

function dc_wiwo_theme($existing, $type, $theme, $path) {
  return array(
    'dc_wiwo_page' =&gt; array(
      'variables' =&gt; array('tweets' =&gt; array()),
      'path' =&gt; drupal_get_path('module', 'dc_wiwo') . '/media';
      'template' =&gt; 'wiwo',
    ),
  );
}