diff --git a/administrator/components/com_fields/helpers/fields.php b/administrator/components/com_fields/helpers/fields.php
index e3345c0a69f90..533f2c382126e 100644
--- a/administrator/components/com_fields/helpers/fields.php
+++ b/administrator/components/com_fields/helpers/fields.php
@@ -53,7 +53,7 @@ public static function extract($contextString)
 	 * Should the value being prepared to be shown in an HTML context then
 	 * prepareValue must be set to true. No further escaping needs to be done.
 	 * The values of the fields can be overridden by an associative array where the keys
-	 * can be an id or an alias and it's corresponding value.
+	 * has to be an id or and it's corresponding value.
 	 *
 	 * @param   string    $context           The context of the content passed to the helper
 	 * @param   stdClass  $item              item
@@ -326,7 +326,7 @@ public static function prepareForm($context, JForm $form, $data)
 		// Creating the dom
 		$xml = new DOMDocument('1.0', 'UTF-8');
 		$fieldsNode = $xml->appendChild(new DOMElement('form'))->appendChild(new DOMElement('fields'));
-		$fieldsNode->setAttribute('name', 'params');
+		$fieldsNode->setAttribute('name', 'com_fields');
 
 		// Organizing the fields according to their group
 		$fieldsPerGroup = array(
@@ -478,7 +478,7 @@ public static function prepareForm($context, JForm $form, $data)
 			if (!is_array($value) && $value !== '')
 			{
 				// Function getField doesn't cache the fields, so we try to do it only when necessary
-				$formField = $form->getField($field->id, 'params');
+				$formField = $form->getField($field->id, 'com_fields');
 
 				if ($formField && $formField->forceMultiple)
 				{
@@ -487,7 +487,7 @@ public static function prepareForm($context, JForm $form, $data)
 			}
 
 			// Setting the value on the field
-			$form->setValue($field->id, 'params', $value);
+			$form->setValue($field->id, 'com_fields', $value);
 		}
 
 		return true;
diff --git a/components/com_contact/controllers/contact.php b/components/com_contact/controllers/contact.php
index 9dfba0bee2546..54fa488afc94b 100644
--- a/components/com_contact/controllers/contact.php
+++ b/components/com_contact/controllers/contact.php
@@ -199,7 +199,7 @@ private function _sendEmail($data, $contact, $copy_email_activated)
 			$body   = $prefix . "\n" . $name . ' <' . $email . '>' . "\r\n\r\n" . stripslashes($body);
 
 			// Load the custom fields
-			if ($data['params'] && $fields = FieldsHelper::getFields('com_contact.mail', $contact, true, $data['params']))
+			if ($data['com_fields'] && $fields = FieldsHelper::getFields('com_contact.mail', $contact, true, $data['com_fields']))
 			{
 				$output = FieldsHelper::render(
 							'com_contact.mail',
diff --git a/libraries/joomla/form/field.php b/libraries/joomla/form/field.php
index 235254ebf6fb3..68ef25b45ff91 100644
--- a/libraries/joomla/form/field.php
+++ b/libraries/joomla/form/field.php
@@ -1082,11 +1082,11 @@ public function appendXMLFieldTag($field, DOMElement $parent, JForm $form)
 	{
 		$app = JFactory::getApplication();
 
-		if ($field->params->get('show_on') == 1 && $app->isAdmin())
+		if ($field->params->get('show_on') == 1 && $app->isClient('administrator'))
 		{
 			return;
 		}
-		elseif ($field->params->get('show_on') == 2 && $app->isSite())
+		elseif ($field->params->get('show_on') == 2 && $app->isClient('site'))
 		{
 			return;
 		}
diff --git a/plugins/system/fields/fields.php b/plugins/system/fields/fields.php
index 2e70d62813e9e..cc9042ed0cac2 100644
--- a/plugins/system/fields/fields.php
+++ b/plugins/system/fields/fields.php
@@ -58,43 +58,24 @@ public function onContentBeforeSave($context, $item, $isNew)
 			return true;
 		}
 
-		$params = new Registry;
-
-		// Load the item params from the request
+		// Load the fields data from the request
 		$data = JFactory::getApplication()->input->post->get('jform', array(), 'array');
 
-		if (key_exists('params', $data))
-		{
-			$params->loadArray($data['params']);
-		}
-
-		// Load the params from the item itself
-		if (isset($item->params))
+		if (!key_exists('com_fields', $data))
 		{
-			$params->loadString($item->params);
+			return true;
 		}
 
-		$params = $params->toArray();
-
 		// Create the new internal fields field
-		$fields = array();
+		$item->_fields = array();
 
 		foreach ($fieldsObjects as $field)
 		{
-			// Set the param on the fields variable
-			$fields[$field->id] = key_exists($field->id, $params) ? $params[$field->id] : array();
-
-			// Remove it from the params array
-			unset($params[$field->id]);
+			// Set the field data on the fields variable
+			$item->_fields[$field->id] = key_exists($field->id, $data['com_fields']) ? $data['com_fields'][$field->id] : array();
 		}
 
-		$item->_fields = $fields;
-
-		// Update the cleaned up params
-		if (isset($item->params))
-		{
-			$item->params = json_encode($params);
-		}
+		unset ($data['com_fields']);
 
 		return true;
 	}
@@ -300,31 +281,6 @@ public function onContentPrepareForm(JForm $form, $data)
 		return true;
 	}
 
-	/**
-	 * The prepare data event.
-	 *
-	 * @param   string    $context  The context
-	 * @param   stdClass  $data     The data
-	 *
-	 * @return  void
-	 *
-	 * @since   __DEPLOY_VERSION__
-	 */
-	public function onContentPrepareData($context, $data)
-	{
-		$parts = $this->getParts($context);
-
-		if (!$parts)
-		{
-			return;
-		}
-
-		if (isset($data->params) && $data->params instanceof Registry)
-		{
-			$data->params = $data->params->toArray();
-		}
-	}
-
 	/**
 	 * The display event.
 	 *