Translation error in variable product types

Hi
Using variables for sizes with woocommerce 2.1.7 and wp. 3.9 gives the site (http://heartandsoles.no/shop-2/mini-chocolaticas/mini-honey/)error on the choose size translation, outputting “Velg en&hellip” instead of “Velg en størrelse”
I have tried to change the word “størrelse” to “nummer” in the product attributes, but it stays the same. Any good advice?

https://wordpress.org/plugins/woocommerce/