Yii Url Paramters - ?f=V Vs. /f/v

Hi everyone,

Do you have any clue why the following only works with "non-yii"-style URLS?

On page A:

<?=CHtml::link('Link', array('edit', 'pk' => $post->primaryKey, 'returnUrl' => $this->createUrl('list')))?>

Which resolves into the URL: /post/edit/pk/311/returnUrl/%2Fpost%2Flist

PostController:

public function actionEdit( $pk = null, $returnUrl = null ) {
    var_dump($returnUrl);
}

This echoes:

string(0) ""

But if I change the URL to

/post/edit/pk/311?returnUrl=%2Fpost%2Flist

It echoes

string(25) "/admin/campaign/conflicts"

Do you have any boileplate code to handle situations like this?