Topic: problem with SimpleViewer in an I-FRAME

I have problems with the SimpleViewer running in an I-FRAME and a Java based head menue.

Please have a look at http://www.basslab.de/index_xxx.html
Choose "Bass" in the head menue and choose any model, you can see that a picture is loading, showing the specific models - when you click at them, the page will be loaded. So please choose the "L-Bow" model and click the "Gallery" link on the L-Bow page, the SimpleViewer is starting and shows the images.

Now use the head menue again and you will see that the model pics are cut where the I-Frame starts !!!!

Any ideas, suggestiosn about this ?