adrotate_clean_trackerdata

Add this line

    $wpdb->query("DELETE FROM `".$wpdb->prefix."adrotate_tracker` WHERE `ipaddress` ='unknown';");

Function now looks like:

/*-------------------------------------------------------------
 Name:      adrotate_clean_trackerdata

 Purpose:   Removes old trackerdata
 Receive:   -none-
 Return:    -none-
 Since:     2.0
-------------------------------------------------------------*/
function adrotate_clean_trackerdata() {
    global $wpdb;

    $removeme = current_time('timestamp') - 86400;
    $wpdb->query("DELETE FROM `".$wpdb->prefix."adrotate_tracker` WHERE `timer` < ".$removeme." AND `ipaddress` > 0;");
    $wpdb->query("DELETE FROM `".$wpdb->prefix."adrotate_tracker` WHERE `ipaddress` ='unknown';");

}