Black in transparent regions - PNG, JPEG alpha channels

I see black in some of the transparent regions of my Windows applications. How can I fix this?

The current Flash Player does not render PNG and JPEG transparency correctly. You can fix this by exchanging the graphic symbol for a new movie clip containing the graphic and enabling bitmap caching for that symbol.

You can turn on bitmap caching by selecting the movie clip on the stage and checking the "use runtime bitmap caching" check box in the movie clip's Properties panel or by setting movie clip's cacheAsBitmap parameter to true via ActionScript.

myGraphc_mc.cacheAsBitmap = true;