problemas no Textarea - Tinymce

Ola, estou utilizando a biblioteca tinymce para usar html dentro de uma textearea e salvar no banco de dados Mysql. Só que estou com problemas na hora de trazer esse dado via json. Esse dado não aparece na textarea quando utilizo o tinymce, mas quando utilizo a textarea normal, sem o tinymce, ele aparece normalmente.

Script do Tinymce

<script type="text/javascript">

	tinymce.init({
 selector: "textarea#elm1",
 theme: "modern",
 plugins: [
 "advlist autolink autosave link image lists charmap print preview hr anchor pagebreak spellchecker",
 "searchreplace wordcount visualblocks visualchars code fullscreen insertdatetime media nonbreaking",
 "save table contextmenu directionality emoticons template textcolor paste fullpage textcolor colorpicker"
 ],
 external_plugins: {
 //"moxiemanager": "/moxiemanager-php/plugin.js"
 },
 content_css: "../views/editos/tests/manual/css/development.css",
 add_unload_trigger: false,
 autosave_ask_before_unload: false,

 toolbar1: "save newdocument fullpage | bold italic underline strikethrough | alignleft aligncenter alignright alignjustify | styleselect formatselect fontselect fontsizeselect",
 toolbar2: "cut copy paste pastetext | searchreplace | bullist numlist | outdent indent blockquote | undo redo | link unlink anchor image media help code | insertdatetime preview | forecolor backcolor",
 toolbar3: "table | hr removeformat | subscript superscript | charmap emoticons | print fullscreen | ltr rtl | spellchecker | visualchars visualblocks nonbreaking template pagebreak restoredraft | insertfile insertimage",
 menubar: false,
 toolbar_items_size: 'small',

 style_formats: [
 {title: 'Bold text', inline: 'b'},
 {title: 'Red text', inline: 'span', styles: {color: '#ff0000'}},
 {title: 'Red header', block: 'h1', styles: {color: '#ff0000'}},
 {title: 'Example 1', inline: 'span', classes: 'example1'},
 {title: 'Example 2', inline: 'span', classes: 'example2'},
 {title: 'Table styles'},
 {title: 'Table row 1', selector: 'tr', classes: 'tablerow1'}
 ],

 templates: [
 {title: 'My template 1', description: 'Some fancy template 1', content: 'My html'},
 {title: 'My template 2', description: 'Some fancy template 2', url: 'development.html'}
 ],

 spellchecker_callback: function(method, data, success) {
 if (method == "spellcheck") {
 var words = data.match(this.getWordCharPattern());
 var suggestions = {};

 for (var i = 0; i < words.length; i++) {
 suggestions[words[i]] = ["First", "second"];
 }

 success({words: suggestions, dictionary: true});
 }

 if (method == "addToDictionary") {
 success();
 }
 }
	});
</script>

Função javascript utilizada para trazer o dado via json e jogar no textarea.

<script type="text/javascript">
$(document).ready(function(){
	$("select[name='macro']").change(function(){
 var laudo = $("textarea[name='laudo']");

 $( laudo ).val('Carregando...');

 $.getJSON(
 'function.php',
 { id: $( this ).val() },
 function( json )
 {
 $(laudo).val( json.macro );

 }
 );
	});
});
</script>

Código PHP utilizado para setar o dado no json

<?php
function retorna($id) {
	$id = ( int ) $id;

	require_once ("../control/CrtMacro.php");
	$obj_macro = new CrtMacro ();
	$dados = $obj_macro->buscar($id);
	$arr = Array ();

	$arr ['macro'] = $dados[0]["descricao"];
	return json_encode ( $arr );
}

if (isset ( $_GET ['id'] )) {
	echo retorna ( $_GET ['id'] );
}
?>

<form>
<label for="laudo">:: Laudo Médico</label>
<textarea id="elm1" name="laudo" cols="125" rows="25"></textarea>
</form>