diff --git a/src/Ratchet/Component/WAMP/Command/Action/CallError.php b/src/Ratchet/Component/WAMP/Command/Action/CallError.php
index ad28763..373e1fa 100644
--- a/src/Ratchet/Component/WAMP/Command/Action/CallError.php
+++ b/src/Ratchet/Component/WAMP/Command/Action/CallError.php
@@ -3,30 +3,76 @@ namespace Ratchet\Component\WAMP\Command\Action;
 use Ratchet\Resource\Command\Action\SendMessage;
 use Ratchet\Component\WAMP\WAMPServerComponent as WAMP;
 
+/**
+ * Respond to a client RPC with an error
+ */
 class CallError extends SendMessage {
+    /**
+     * @var string
+     */
     protected $_id;
 
+    /**
+     * @var string
+     */
     protected $_uri;
 
-    protected $_desc;
+    /**
+     * @var string
+     */
+    protected $_desc = '';
 
-    public function setError($callId, $uri, $desc) {
+    /**
+     * @var string
+     */
+    protected $_details;
+
+    /**
+     * @param string The unique ID given by the client to respond to
+     * @param string The URI given by the client ot respond to
+     * @param string A developer-oriented description of the error
+     * @param string|null An optional human readable detail message to send back
+     * @return CallError
+     */
+    public function setError($callId, $uri, $desc = '', $details = null) {
         $this->_id   = $callId;
         $this->_uri  = $uri;
         $this->_desc = $desc;
 
-        return $this->setMessage(json_encode(array(WAMP::MSG_CALL_ERROR, $callId, $uri, $desc)));
+        $data = array(WAMP::MSG_CALL_ERROR, $callId, $uri, $desc);
+
+        if (null !== $details) {
+            $data[] = $details;
+        }
+
+        return $this->setMessage(json_encode($data));
     }
 
+    /**
+     * @return string|null
+     */
     public function getId() {
         return $this->_id;
     }
 
+    /**
+     * @return string|null
+     */
     public function getUri() {
         return $this->_uri;
     }
 
+    /**
+     * @return string
+     */
     public function getDescription() {
         return $this->_desc;
     }
+
+    /**
+     * @return string|null
+     */
+    public function getDetails() {
+        return $this->_details;
+    }
 }
\ No newline at end of file
diff --git a/src/Ratchet/Component/WAMP/Command/Action/CallResult.php b/src/Ratchet/Component/WAMP/Command/Action/CallResult.php
index 4df370d..b65d062 100644
--- a/src/Ratchet/Component/WAMP/Command/Action/CallResult.php
+++ b/src/Ratchet/Component/WAMP/Command/Action/CallResult.php
@@ -4,12 +4,24 @@ use Ratchet\Resource\Command\Action\SendMessage;
 use Ratchet\Component\WAMP\WAMPServerComponent as WAMP;
 
 /**
+ * Respond to a client RPC
  */
 class CallResult extends SendMessage {
+    /**
+     * @var string
+     */
     protected $_id;
 
+    /**
+     * @var array
+     */
     protected $_data;
 
+    /**
+     * @param string The unique ID given by the client to respond to
+     * @param array An array of data to return to the client
+     * @return CallResult
+     */
     public function setResult($callId, array $data = array()) {
         $this->_id   = $callId;
         $this->_data = $data;
@@ -17,10 +29,16 @@ class CallResult extends SendMessage {
         return $this->setMessage(json_encode(array(WAMP::MSG_CALL_RESULT, $callId, $data)));
     }
 
+    /**
+     * @return string|null
+     */
     public function getId() {
         return $this->_id;
     }
 
+    /**
+     * @return array|null
+     */
     public function getData() {
         return $this->_data;
     }
diff --git a/src/Ratchet/Component/WAMP/Command/Action/Event.php b/src/Ratchet/Component/WAMP/Command/Action/Event.php
index b711b74..9bf2e90 100644
--- a/src/Ratchet/Component/WAMP/Command/Action/Event.php
+++ b/src/Ratchet/Component/WAMP/Command/Action/Event.php
@@ -14,6 +14,6 @@ class Event extends SendMessage {
      * @return Event
      */
     public function setEvent($uri, $msg) {
-        return $this->setMessage(json_encode(array(WAMP::MSG_EVENT, $uri, (string)$msg)));
+        return $this->setMessage(json_encode(array(WAMP::MSG_EVENT, $uri, $msg)));
     }
 }
\ No newline at end of file
diff --git a/src/Ratchet/Component/WAMP/WAMPServerComponent.php b/src/Ratchet/Component/WAMP/WAMPServerComponent.php
index c60f6c3..6e3e353 100644
--- a/src/Ratchet/Component/WAMP/WAMPServerComponent.php
+++ b/src/Ratchet/Component/WAMP/WAMPServerComponent.php
@@ -84,7 +84,6 @@ class WAMPServerComponent implements WebSocketComponentInterface {
         $conn->WAMP                = new \StdClass;
         $conn->WAMP->sessionId     = uniqid();
         $conn->WAMP->prefixes      = array();
-        $conn->WAMP->subscriptions = array();
 
         $wamp = $this;
         $conn->WAMP->addPrefix = function($curie, $uri) use ($wamp, $conn) {
diff --git a/tests/Ratchet/Tests/Mock/WAMPComponent.php b/tests/Ratchet/Tests/Mock/WAMPComponent.php
new file mode 100644
index 0000000..9473e85
--- /dev/null
+++ b/tests/Ratchet/Tests/Mock/WAMPComponent.php
@@ -0,0 +1,36 @@
+<?php
+namespace Ratchet\Tests\Mock;
+use Ratchet\Component\WAMP\WAMPServerComponentInterface;
+use Ratchet\Resource\ConnectionInterface;
+
+class WAMPComponent implements WAMPServerComponentInterface {
+    public $last = array();
+
+    public function onCall(ConnectionInterface $conn, $id, $procURI, array $params) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+
+    public function onSubscribe(ConnectionInterface $conn, $uri) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+
+    public function onUnSubscribe(ConnectionInterface $conn, $uri) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+
+    public function onPublish(ConnectionInterface $conn, $uri, $event) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+
+    public function onOpen(ConnectionInterface $conn) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+
+    public function onClose(ConnectionInterface $conn) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+
+    public function onError(ConnectionInterface $conn, \Exception $e) {
+        $this->last[__FUNCTION__] = func_get_args();
+    }
+}
\ No newline at end of file