Trouble with wp_list_pages and permalinks

I have this in my sidebar:

<h1><?php _e(‘Pages’); ?></h1>
<?php wp_list_pages(‘title_li=’); ?>

It works fine except when I enable permalinks. With permalinks, when I visit a page, i.e. /about-me/, the page displays fine but wp_list_pages no longer displays the list of pages. The anchor text is missing, so nothing shows up.

I’ve tried numerous templates, including the classic, and it seems broken in all of them.

Any ideas?