List pages broken

I just downloaded 2.5 and my “list pages” function is broken. here is the error i get:

Warning: Invalid argument supplied for foreach() in /home/rgordon8/public_html/fenderbluesjunioramps/wp-includes/post.php on line 1783

here is the page so you can see:
http://fenderbluesjunioramps.com/mods-parts-extras/ (top right nav)

Here is the code i have in the theme:

?php 

	if ($aOptions['show_subpages']) :

		global $id;
		$aSubPages = get_page_children($id, '');
		if (count($aSubPages) > 0) :

?>

					<div id="child_pages">
						<h3>More Pages</h3>
						<ul class="icon jump">
                                                <?php foreach ($aSubPages as $page) { echo('<li><a href="' . $page->guid . '">' . $page->post_title . '</a></li>'); } ?>				</ul>

					</div>