Yes, you are right, it seems to be the navigation arrows that taking all this space. When placing the navigation arrows "center" instead of "bottom", instead there is a lot of space between main-picture and thumbs. Is there anyway I can remove the navigation arrows? I can't find them in CSS.

The thumbs doesn't use the right area to 100%. In my example three rows should have room without problem, but it only use two rows.
https://dl.dropbox.com/u/2228945/thumbs_fill_hight.jpg

I'm using Juicebuilder-Pro application to build a gallery with thumbnails in a column to the right. But I can't get rid of the space of 10px between the main image and the thumbnail-row. The image is set to "fill" and image padding=0. But still there is 10px gap between. When having thumbnails at bottom or top there is no gap.