Hi. As this post remains unanswered I just thought I'd add my experience and the solution that worked for me.
I shut down my computer, started it back up again, problem solved.
I was setting up various charts, list boxes, etc and dragging them around to where I wanted them when I suddenly found I was no longer able to move objects. I had not been into any settings (user, document, sheet or object) so I knew it couldn't be to do with the "Allow Move/Size" options, despite this I still checked an sure enough, the box still had a tick in it.
I quit QlikView and started it again but his did not work. I opened a previous version of the document and I was able to drag objects around. Eventually, I restarted my computer and this seemed to cure the problem.