--- user_pref_api.php	Tue Feb 09 14:50:38 2010
+++ user_pref_api-patched.php	Tue Feb 09 14:45:42 2010
@@ -214,7 +214,7 @@
 
 	$query = "SELECT *
 				  FROM $t_user_pref_table
-				  WHERE id IN (" . implode( ',', $c_user_id_array ) . ') AND project_id=' . db_param();
+				  WHERE user_id IN (" . implode( ',', $c_user_id_array ) . ') AND project_id=' . db_param();
 
 	$result = db_query_bound( $query, Array( (int)$p_project_id ) );