i have the same issue with flickering video on Z64 Android latest firmware. I tried all versions of Android and still the same issue. I have tried in two different TV's Samsung 50" and 55" still the same issue. I tried to change the HDMI from 1920x1080 60hz to 50hz to 30hz even to HD only still the same. Most of the time when i close the application as an example Youtube the screen goes for a second black and then the TV shows that it was just connected again HDMI 2 for example at the corner and then its stable until i swap the app again.