The following error message comes up only when Akismet 2.5.6 is activated:
Warning: Missing argument 2 for wp_widget() in /usr/local/pem/vhosts/267049/webspace/siteapps/143501/htdocs/wp-includes/widgets.php on line 76
Version 2.5.3 had been working without problems. I'd like to go back to it.