2 compiler errors with steamVR for unity

I tried to play around with SteamVR, even if i have no dev version yet and waiting eagerly the arrival of the Vive consumer version.

But i got 2 compiler errors with unity 5.4.0b10 right at the beginning:

Assets/SteamVR/Scripts/SteamVR_UpdatePoses.cs(17,36): error CS0103: The name `TargetEyeMask' does not exist in the current context

Assets/SteamVR/Scripts/SteamVR_UpdatePoses.cs(17,24): error CS1061: Type `UnityEngine.Camera' does not contain a definition for `targetEye' and no extension...

2 compiler errors with steamVR for unity