Hi,
I lost Context3D on andoid devices - HTC 3D EVO (Android 4.0.3) and Sony Ericson WT19i (Android 4.0.4). On Samsung Galaxy Tab 2 not lost Context3D.

I use Away3D 4.0.1 Aplha from this site, Flash Player 11.7 and Adobe Air 3.7.
In windows when I press CTRL+ALT+DEL everything is ok - not lost context.

Problem is when I have running application/game with away3D, and lock my android device and then unlock it -> lost context (black screen instead view3D).
When I have running application/game and go to home screen and then lock device and unblock it and then switch to my app -> everything is ok.

I dont know what I am doing wrong (In windows dont lost context3d, and some andorid devices dont too). Its very frustrating when its working on some devices :/

Maybe I am missing something in my code (Attached class in which init away3d)

Thanks for help.

I had the same problem.
The solution was:

1.Add this code at the beginning of your app:
NativeApplication.nativeApplication.systemIdleMode = SystemIdleMode.KEEP_AWAKE;

2.add this code in the resize event:
if (view.stage3DProxy != null)
  view.render();

And it did the trick…

Thanks very much !