Getting RenderMode property in new Window

Hi,

     I am using AIR 3.1 SDK. I am creating a new window in the main application

var window3DInstance:Window3D=new Window3D();

window3DInstance.open(true);

In the newly created window I am trying to load some 3D contents. Then It generates the Following Error

Error #2044: Unhandled ErrorEvent:. text=Error #3702: Context3D not available.

I can able to load the 3D contents in the main application window.Then from my research I found that to use the stage3D support we need to have the rendermode to 'gpu' or 'direct'. I am setting the rendermode in the application descripter file.

<renderMode>direct</renderMode>

But the issue is that this renderMode property is not getting in the newly created window. I

Is there any solution for this?

Thanks in advance