cart broken - does not refresh properly - PS1.4.9 alt template

[BoKr]

Hello

 

we went live this week and thougth all was fine BUT it wasn't. The cart is broken!

 

We use OPC and noticed with pain that when a user is logged in and clocks a second time on the cart blocks title or its 'order' button then our template brakes totally. Normally the opc.php should be being loaded (I assume so) but it does not. It only appears a white frame with the breadcrumb gone and the footer! They totally disappear.

I am absolutely frustrated and can not solve this alone.

 

Just to have it said twice, it only happens if logged into account. Else there is no problem with loading the cart again via clicking into cart block or pressing F5 in the browser.

 

Besides:

When you delete items from the cart while being logged in then the cart start working again if it was totally emptied!?

 

 

The domain is:

www.gruenes-spielzeug.de

 

It is in German but please do not hestitate to contact me if you have any questions and if you can help me!

 

I thank you very much

Boris

 

before you refresh:

 

and after refresh:

 

 

I do not know but as said breadcrumb and footer diasappear and all goes up in the layout so to say.