Jittering in 2D Image Targets

We experience a lot of jitter with even the simplest setup:- mounted camera with mounted 2d marker in an evenly lit environment- World Center Mode = FIRST_TARGET- Focus Mode = FOCUS_MODE_CONTINUOUSAUTO on Start- Extended Tracking = enabledEven though everything is motionless the tracker continuously updates & adjusts positions resulting in a strong jitter (even with vuforia sample image targets).We tried the camera smoothing script (see below) but it results in lack when the camera is moved later which means its not a solution.Anybody found a solution yet? Your help is much appreciated!Environment: Windows 10, Unity 5.3.1 32-bit, Vuforia SDK v5.0.10Camera smoothing script: https://developer.vuforia.com/forum/unity-3-extension-technical-discussion/filter-camera-position-and-rotation-avoid-jitter