Enter/Exit fullscreen has a flashing black screen effect.

Repro Steps:

1. Install 4.0.0a1 WebPlayer full from above link
2. Launch Facebook Margaritaville on IE 9
3. Progress through some clicks until the fullscreen button appears in the bottom right hand corner
4. Enter fullscreen and observe a flash of a black screen
5. Observe same happens when exiting fullscreen

Desired outcome: No black screen flash, exit/enter fullscreen should be smooth with no artifacts.

Not present in recent 3.5 release.

Using 4.0.0f7 plugin this graphical flashing effect occurs in both stable and release channels

Browsers tested:

IE9: reproduces
FF 17: reproduces
Chrome 24.0.1312.14 beta-m: reproduces

GPU: NVIDIA GeForce GTX 260