I am trying to rearrange the icons on my Unity launcher. Sometimes I can just drag and drop an icon without difficulty. But other times when I attempt to drag an icon all icons on the launcher slide together. Why is that? What can I do to make sure my dragging and dropping performs one of these actions or the other?
My observation is that:
You slide all icons up and down if you click and hold an icon and then move the mouse vertically.
You can move one single icon inside the launcher by clicking and holding it and then first moving a bit horizontally to free it. After that you can drag it wherever you want.
I am currently on XFCE so I can't check, but this is how I remember it from Unity.