WooCommerce Translations don’t work

Hello,
I have a problem concerning a website I previously created for one of our customers. When buying a product in the woocommerce-shop, for example via http://www.prolac-beschriftungen.de/produkt/schablone , there are a few english strings in the shopping-cart. I need to translate them to German, but the str_replace-Filter that we usually apply for that kind of tasks doesn’t work. Does anyone have an idea how I could solve this? It’s just a few single words, so a quick-and-dirty solution would be perfect.
Thank you very much for your help,
Silvanovic

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