Thanks Shadow and balinor, so what you're basically saying is that when the group's name is for example 'Size' and you have 'Small, 'Medium' and 'Large', I should put 'Small' in the 'Option Name' place, I tried that but it doesn't work and if this would work; what about the others; medium and large?
EDIT: somehow I suddenly got it working not ... don't ask me why
Working with 4.1.3!