CacheAsBitmap and setting Alpha?

I am experiencing a problem with setting the cacheAsBitmap and alpha properties on TV devices. (This is not an issue on my desktop.)

I'd like to set a display object's cacheAsBitmap property to true.

The display object has an alpha transparency of .5.

If I cache the Bitmap while the alpha is set to .5, then the display object appears to have a transparency of .25.

I've tried to set the alpha to 1, cache the bitmap, and then set the alpha to .5 --  this does not work.

this.alpha = 1;

this.cacheAsBitmap = true;

this.alpha = .5;

What does work is if I delay in setting the alpha. If i set the alpha to 1, cache the bitmap, wait 2 seconds, and then set the alpha to .5 --- then that works!

this.alpha = 1;

this.cacheAsBitmap = true;

var timer:Timer = new Timer(2000,1);

timer.addEventListener(TimerEvent.TIMER_COMPLETE, onTimer);

timer.start();

protected function onTimer(e:TimerEvent):void {

                              this.alpha = .5;

}

However, this is less than ideal. I want to cache the bitmap immediately while the alpha is set to .5.

Is there some trick to do this?