Problem, when click product with attribut, prices change ??

[Donner]

Hi i encounter this problem

in Categories the prices are correct, when click the product, the price chances, but i have not given the attribut any value.

what can be the reason ?

see the products here and see

see attached photo

any ideas

I can see the price changes when i enter the product, just 1 secund, and then it has changed.

Jesper