Deprecated Functions in Post Indexer

getting this error message in my php logs. Think this function is deprecated now and it throwing errors to php.

[21-Sep-2012 03:34:13] PHP Notice: is_plugin_page is deprecated since version 3.1 with no alternative available. in /wp-includes/functions.php on line 2640

[21-Sep-2012 03:34:13] PHP Notice: Undefined index: key in /wp-content/plugins/post-indexer/post-indexer.php on line 41