I created a bookmarks-folder, then attempted to drag a bookmark to that newly created, empty folder. This seems to be impossible. I had to choose "add bookmark", which moved another bookmark, which I did not intend to move, to that folder. After this I could drag the bookmark I originally wished to move there.
Even then it's quite difficult to get the bookmark to end up in the intended folder. Often it ends up just over or below it.
Ronery,
if you talk about Bookmark Manager - it's not too hard:
just hold the wished link on the folder - and it 'opens' so you could place link there...
I have a similar problem. When I open the bookmark manager, create a new folder and rename it, it's impossible to put a bookmark inside. I have to create a folder, drag something inside and then rename it. Otherwise it doesn't work.