This may not be a problem. If you are trying to drag a file within a single folder and finding that it doesn't move, this is not a problem. It is the way things are supposed to work. Finder is keeping the files auto arranged for you.
To move them around within a window, essentially arranging them yourself, select View, View Options from Finder's menu, and clear the check box near the bottom that says Keep Arranged By. Things will "unarrange" at that point and you can move them as you wish.