Some ASIN Items are showing some are not, all are available in Germany

I have a list:

http://michaelkowalczyk.eu/allgemein/android-4-x-smartphones-2013-mit-wechselakku-und-sd-karte/

When i add for example a ASIN B007VCRRNS for Samsung S3 (http://www.amazon.de/Samsung-Smartphone-Super-AMOLED-Touchscreen-Megapixel-pebble-blue/dp/B007VCRRNS) in pebl blue as Shortcode:

[amazon-element asin=”B007VCRRNS” fields=”sm-image,button”]

it will display the item correctly after saving the table.

After some time, lets say 30 Minutes the product is not displayed anymore.

Strangely this is just happening for a few models. The others are displayed fine.

Locale is DE and the phone model is also available in Germany.

Hint: On the Page some signs appear when the products are not displayed anymore ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–> ]–>

Any Idea on this?
Thanks and Greetings!

Michael

http://wordpress.org/plugins/amazon-product-in-a-post-plugin/