Themes not showing correctly ?

Hi,

I was browsing some themes here at the WP site and some of them aren’t displaying properly. Fe:
http://wordpress.org/extend/themes/lobeira
http://wordpress.org/extend/themes/businesso

They don’t work on the preview, nor on my blog.

This is probably something really stupid, but I just can’t seem to make them work.

Here’s how they look:
http://img26.imageshack.us/my.php?image=previewf.jpg

Thanks!