linked_logo always emty

Hi

The linked logo part of the theme always seem to be empty for me what ever I do.

In preprocess page in base theme the $logo variable is also always empty so the logo_img variables is never populated.

$variables['logo_img'] = '';
if (!empty($variables['logo'])) {
$elements = array(
'#theme' => 'image',
'#attributes' => array(
'src' => $variables['logo'],
'alt' => strip_tags($site_name) . ' ' . t('logo'),
'title' => strip_tags($site_name) . ' ' . t('Home'),
'class' => array('logo'),
)
);

$variables['logo_img'] = $elements;
}