Hi, There is nothing wrong with the short code.
When I checked your web page's source code, I noticed there aren't any javascript tag showing. Javascript tag is used to show Flash player, so they are absolutely required.
As I remember, some security plugin remove javascript tag from the post content. That's why I suspected you may have such plugin turned on.
Why don't you set up a new wordpress in a separate folder and try out Hana Flv Player ? That will confirm if my assumption is correct or not.
Here is the HTML source code of your page
<html>
<head>
<meta name='robots' content='noindex,nofollow' />
<link rel="EditURI" type="application/rsd+xml" title="RSD" href="http://www.pixel2motion.de/wordpress/xmlrpc.php?rsd" />
<link rel="wlwmanifest" type="application/wlwmanifest+xml" href="http://www.pixel2motion.de/wordpress/wp-includes/wlwmanifest.xml" />
<link rel='index' title='Pixel2Motion' href='http://www.pixel2motion.de/wordpress' />
<link rel='start' title='Die Entdeckung der Currywurst // DVD-Authoring // Kunde: Legend Home Entertainment // Januar 2010' href='http://www.pixel2motion.de/wordpress/feature-1' />
<link rel='prev' title='asdf' href='http://www.pixel2motion.de/wordpress/asdf' />
<link rel='next' title='asdf' href='http://www.pixel2motion.de/wordpress/asdf-2' />
<meta name="generator" content="WordPress 2.9.1" />
<link rel='canonical' href='http://www.pixel2motion.de/wordpress/sdafsdaf' />
</head>
<body>
<h2>sdafsdaf</h2>
<p>
<div >
<div id='hana_flv_flow_1'></div>
</div>
</p>
</body>
</html>