printlinks.css does not get included under certain conditions

When a 403 error redirects to a page with print links, the links are displayed but the printlinks.css file might not be linked in.
The only way I found to overcome this problem is to duplicate entries from printlinks.css into theme's style.css.
As an example:

• go to http://www.datasphere.ch/admin: you will be redirected to the home page because you have no admin permission. Note also that the site theme is restored using patch at http://drupal.org/node/759836: without it, you'll get the site home page with the admin theme (that has no print links).
• refresh the page
• using something as firebug, browse the html head section: you'll see no link to printlinks.css, although the links are on the page.