Bug Unity creates doubles when dragging from project window to scene or Hierarchy.

OS: DeepinOS (based on Ubuntu 14.04).

When dragging prefabs from project window to scene view, or into the hierarchy, Unity create a double of the object/asset. First noticed this when I created a camera from a prefab which gave an error on Play claiming "there are two audio listeners in the scene". It was confirmed when I added something else and zoomed out enough from the scene. The double doesn't show up in hierarchy until a reload of the scene.

Not sure if it's just me, but maybe a second opinion is in order. Can anyone confirm?