I found this error message:
Strict Standards: Declaration of Walker_IntelliWidget::start_el() should be compatible with Walker::start_el(&$output, $object, $depth = 0, $args = Array, $current_object_id = 0) in /Volumes/Own/immanuel/Sites/design/aqua-soleil/wp-content/plugins/intelliwidget-per-page-featured-posts-and-menus/includes/class-walker-intelliwidget.php on line 47
Seems 3.6 has been good at break many plugins...
http://wordpress.org/plugins/intelliwidget-per-page-featured-posts-and-menus/