How to link to item from the file show page?

I'm trying to put a link on a file metadata show page to get back to the item (that the file belongs to) show page. I tried to use similar function as in the /admin/themes/default/files/show.php:

link_to_item('Back to item', array(), 'show', $file->getItem());

but is returns nothing (no HTML).
Can anybody help?

That's working for me when I put it on a files/show.php page for the theme.

Are you echoing out the line?

<?php echo link_to_item('Back to item', array(), 'show', $file->getItem()); ?>

I really missed the echo function in my code ;-)
I can only blame the last weekend's daylight saving time shift.
Thanks a lot!