ChrisSamuelAt line 52 of httpbl.php you need to explicitly cast $results as an (array) to prevent an ugly PHP warning at the top of each page which says:
Warning: Invalid argument supplied for foreach() in /var/www/htdocs/wp-content/plugins/httpbl/httpbl.php on line 52
In other words, it becomes:
foreach ((array)$results as $row) {
janstepien