Which other plugins are active? Do you have the request_saver plugin enabled?
Here are the installed plugins. no request_saver.
$rcmail_config['plugins'] = array('filesystem_attachments','automatic_addressbook','jqueryui','calendar','markasjunk',
'vcard_attachments','vcard_attach','archivefolder','google_contacts','settings','taskbar','sound_notifier','sticky_notes',
'msglistcols','remember_spliter','remember_me','emoticons','newuser','savepassword','remember_skin','password','accounts','message_highlight');