diff --git a/model/PFAHandler.php b/model/PFAHandler.php
index a7ea3fc3..169b88af 100644
--- a/model/PFAHandler.php
+++ b/model/PFAHandler.php
@@ -33,18 +33,18 @@ abstract class PFAHandler {
      * @var string (default) name of the database table
      * (can be overridden by $CONF[database_prefix] and $CONF[database_tables][*] via table_by_key())
      */
-    protected $db_table = null;
+    protected $db_table;
 
     /**
      * @var string field containing the ID
      */
-    protected $id_field = null;
+    protected $id_field;
 
     /**
      * @var string  field containing the label
      * defaults to $id_field if not set
      */
-    protected $label_field = null;
+    protected $label_field;
 
     /**
      * field(s) to use in the ORDER BY clause
@@ -52,7 +52,7 @@ abstract class PFAHandler {
      * defaults to $id_field if not set
      * @var string
      */
-    protected $order_by = null;
+    protected $order_by;
 
     /**
      * @var string
@@ -896,7 +896,7 @@ abstract class PFAHandler {
     }
 
     /**
-     * @return return value of previously called method
+     * @return mixed return value of previously called method
      */
     public function result() {
         return $this->result;
diff --git a/model/Shell.php b/model/Shell.php
index 84a3f838..3f5141e4 100644
--- a/model/Shell.php
+++ b/model/Shell.php
@@ -36,7 +36,8 @@ class Shell {
      * @var object
      * @access public
      */
-    public $Dispatch = null;
+    public $Dispatch;
+
     /**
      * If true, the script will ask for permission to perform actions.
      *
@@ -64,28 +65,28 @@ class Shell {
      * @var string
      * @access public
      */
-    public $shell = null;
+    public $shell;
     /**
      * The class name of the shell that was invoked.
      *
      * @var string
      * @access public
      */
-    public $className = null;
+    public $className;
     /**
      * The command called if public methods are available.
      *
      * @var string
      * @access public
      */
-    public $command = null;
+    public $command;
     /**
      * The name of the shell in camelized.
      *
      * @var string
      * @access public
      */
-    public $name = null;
+    public $name;
 
     /**
      *  Constructs this Shell instance.
diff --git a/model/VacationHandler.php b/model/VacationHandler.php
index d8a9d3af..c9ed41d2 100644
--- a/model/VacationHandler.php
+++ b/model/VacationHandler.php
@@ -199,18 +199,18 @@ class VacationHandler extends PFAHandler {
         $boolean = ($row['active'] == db_get_boolean(true));
         # TODO: only return true and store the db result array in $this->whatever for consistency with the other classes
         return array(
-            'subject' => $row['subject'],
-            'body' => $row['body'],
-            'active'  => $boolean ,
-            'interval_time' => $row['interval_time'],
-            'activeFrom' => $row['activefrom'],
-            'activeUntil' => $row['activeuntil'],
+            'subject' => isset($row['subject']) ? $row['subject'] : null,
+            'body' => isset($row['body']) ? $row['body'] : null,
+            'active'  => $boolean,
+            'interval_time' => isset($row['interval_time']) ? $row['interval_time'] : null,
+            'activeFrom' => isset($row['activefrom']) ? $row['activefrom'] : null,
+            'activeUntil' => isset($row['activeuntil']) ? $row['activeuntil'] : null
         );
     }
     /**
      * @param string $subject
      * @param string $body
-     * @param string $interval_time
+     * @param int $interval_time
      * @param string $activeFrom - something strtotime understands
      * @param string $activeUntil - something strtotime understands
      * @return boolean