Importing articles - placeholder image

Hi

I have imported several articels with a "read-more-section" into Easy-Blog. Frontpage looks good:

http://new.hjop.ch/

But as soon as I open one of the blogs, it shows me this "placeholder-image" and below of it the picture:

http://new.hjop.ch/index.php/biwak-schnebelhorn

Any help on this would be appreciated.

Thanks
Michael