Custom fields adds Gratis text string after feature

[LAMF]

I have made three different custom fields in my VM shop. One for sizes, one for colours and one for Models.
If I go into the properties of a product and add the sizes custom field and then define th different sizes there is also a column with Pices.
I leave them at 0 SEK (Swedish Kronor) and then when saved and the product is viewed in the shop front end there's an additional text to the sizes values saying + Gratis (Gratis = For free).
Why is that?
I have tried to add the real value for the product in the Price column in the Custom fields tab but that only adds that price to the original pride and gives the double price.
I want the + Gratis text taken away how do I do that?
Or do I have to define a price in each if the attributes in the custom fields?
How can I get only the original price and only have the size attributes, S, M, L, XL for example without any + Gratis or other orice value?
This is weird and something that probably happened after the upgrade to 2.0.14.
Forgot to post an example so here's a sample URL:
http://www.stigsbergsgard.se/index.php/handla/for-ryttaren/27/pikeur-judy-kontrast-detail