Imported From: http://groups.google.com/group/in-portal-bugs/browse_thread/thread/477e8e3bb9610a8d#
core/kernel/application.php
function HREF($t, $prefix = '', $params = null, $index_file = null)
Default "null" value for "$params" variable causes following code to trigger "array_key_exists(): The second argument should be either an array or an object" notice:
core/kernel/application.php
if (array_key_exists('use_section', $params)) {
According to general development rules this should be changed either to:
function HREF($t, $prefix = '', $params = Array(), $index_file = null)
or:
if (is_array($params) && array_key_exists('use_section', $params)) {