1. Do not use the WordPress Plugin (nor the php.ini suggestion) when using the release candidates.
2. The source code for the front page of your site consists of this:
<frameset rows="100%,*" border="0">
<frame src="http://shortwavepirate.info/pw/wordpress/" frameborder="0" />
<frame frameborder="0" noresize />
</frameset>
There is no Woopra code, no content code, nothing but that. It acts as a redirect to the shortwavepirate.info site, and Woopra does not work with redirects nor frames in this situation. Woopra is trying to track the main site, not the shortwavepirate.info site, which is probably where you have the Woopra code.
As an additional note, while you are cleaning up the underlying code of your site, you might want to drop the "wordpress" in the WordPress install as it dilutes your SEO, as does the frame. Just install WordPress to your root directory.