Using Camera.setViewOffset with Reflector stretches the reflected texture


I’m trying to move the scene without changing perspective with the camera.setViewOffset function.
However, when using Reflector, if set the offset x value above a certain level, the reflected texture is stretched.
The offset y value does not seem to be affected.

Here’s a fiddle. You can see this by adjusting the gui on the right.

And with Water2, the reflected texture is not stretched, but moves in the opposite direction of the object.

What did I miss?
How can I fix this?

Thank you.