Add to cart button disappears

Hi,
I don't know why, but the Add to cart button disappears and I have no clou where I mixed up something.
Catalogue modus is off, All products have prices.
I checked all hints from the forum about that, but no luck

please check the link to see it:

www.selbstverteidigungskurs.ch/en/shop/p.../category_pathway-10

Does anyone have an idea?

I run the business version 1.5.7 on Joomla 1.5.26

Hello,

Do you have restrictions in your products ? like the quantity of your products to 0, a sale start date in the future or a sale end date in the past ?

No restriction, quantity is set to a certain number or unlimited, no date set for start or end.

Some additional information:

I do have another hika-web shop 1.5.7 with Joomla 2.5.3 and there everything is working fine. The settings in

System - configuration - display
Dispaly - content menu
Display - content modules

are identical.

Some strange behaviour is when I set in
Display - content modules - "the Associated products listing for category listing menu 161" - under Parameters for Products Display 'Add to cart' button to Yes, than I got a "Choose Option" Button one level before...

YOUR ARE AMAZING!
It works!!

Thank you very much.