OVRCameraRig mirrored view on main screen gets stretched. **SOLVED**

Problem: I use only one camera in Unity (OVRCameraRig) as it is described in the Oculus SDK documentation, but the problem is, that the mirrored view on the main screen gets stretched after I activate the HMD and disable it again with VRSettings.enable = false and showDeviceView = false). Please help me.

Unity Version 5.4.2b025
Oculus Utilities:  V1.10.0

Thanks in advance.

Bernhard Lutz

EDIT: 

This line of code saved my day:
Camera.main.ResetAspect();