Index: canonical.php
===================================================================
--- canonical.php	(revision 13781)
+++ canonical.php	(working copy)
@@ -367,9 +367,12 @@
 
 	$where = $wpdb->prepare("post_name LIKE %s", get_query_var('name') . '%');
 
-	// if any of post_type, year, monthnum, or day are set, use them to refine the query
+	// If any query variables are present that can refine the query, use them
 	if ( get_query_var('post_type') )
 		$where .= $wpdb->prepare(" AND post_type = %s", get_query_var('post_type'));
+	elseif ( get_query_var('name') && ! get_query_var('pagename') ) // If the request has specified a "name" var, but not a "pagename" var, it's a request matched upon the Post Permalink structure. not a page structure.
+		$where .= $wpdb->prepare(" AND post_type = %s", 'post');
+
 	if ( get_query_var('year') )
 		$where .= $wpdb->prepare(" AND YEAR(post_date) = %d", get_query_var('year'));
 	if ( get_query_var('monthnum') )