Porfolio, gallery

Hi BlueOwl,
How do you add more pictures in a portfolio-item?
I have selected the “Gallery” option at the right site, but I’m not able to add more than one image. I have also read another issue about this, but something is wrong when I do it.
And if I add a media at the left site in the toolbar, then I don’t get more images underneath the first related image.

http://test.neming.dk/portfolio_item/691/

Best regards,
Henrik