Model assembly Output question

I have attached a screenshot were I am testing a simple model in karamba. Although I am using one cross section for my panels and one material it seems that i am getting out 2 materials and 3 cross sections. This has happened in previous examples that I have been using karamba and it looks like there is a default material embedded in karamba's component. Any ideas would be more than welcome.

Post edit: djordje clarified the issue with the materials saying that as soon as you create your own material and label it then only that material is taken under account. The issue with the cross sections is still up.