Hi @happytester
Sorry for the inconvenience @gongomgra but I could not create an account on Testlink forum yet and as the question is already asked here I thought it would be helpfull to share what I found.
I have the same problem and found that this is a bug with the first scroller : you can only move the first items visible when the scroller is at the top (even if you scrolled down). As a workaround, I hide Filters
and collapse all folders and then I can move more visible items.