Win 8 Does Not Support Transparent Backgrounds For Account Picture?

Hi All!

I set my Account Picture to an image file (.png format) with a transparent background, however, the background shows up as black instead of clear.

Here is the original image (shown in Paint.NET). Note the transparency.


And here is what the image looks like as my Account picture.


Are there any other image formats that Windows 8 supports that would allow me to have a transparent background for my Account picture?

Thanks!