phptemplate_features cannot be overriden by using themes

if you have a template using the phptemplate engine,
then by default some options are offered for configuration: logo, slogan etc ...
Unfortunately, if you are not interested by some of default features , you can't remove them by overriding phptemplate_features function.
Let me explain better by using an example.
Let say your template have the name "yellow".
Then in your template.php file you put the function:

function yellow_features() {
  return array(
       'toggle_logo',
       'toggle_favicon',
       'toggle_name',
       );
}

Unfortunately, such function will just be ignored,
and you'll still have all the default options.

I think the problem rely in system.module near line 1920:

 $features = function_exists($themes[$key]->prefix .'_features') ? call_user_func($themes[$key]->prefix .'_features') : array();

when the code is executed, the function phptemplate_features is automatically choosed by default.