Unity made some changes internally to the Camera viewport rects to fix viewport issues in VR. With this change, the Screen.width and height no longer represent the resolution of the HMD. Screen represents the game view and the HMD resolution is now represented by VRSettings.eyeTextureWidth and VRSettings.eyeTextureHeight. So if you raycast using the Game View's width and height, the ray will be incorrect for VR cameras unless your Game view resolution is the same as the HMD.
I'm sure this would be very difficult to troubleshoot and not to mention all the Oculus samples will be broken.
