lines 1167 & 1168:
preg_match($anchorPattern, $text, $matches);
if ($matches[2] == "") return $text;If the author link isn't a link, just text, then $matches[2] doesn't exist, which throws an "Undefined offset" notice. This fixes it:
if ( empty( $matches[2] ) ) return $text;http://wordpress.org/extend/plugins/google-analytics-for-wordpress/
