Transparent PNG image with TImageList

I'm using Delphi XE.

I added a TAdvGlowButton on my form and added a TImageList with one transparent PNG image as its source for images. When I view the form in th开发者_如何学Ce design mode, the button looks exactly right and the image is transparent. However, when I run the program, the background of the image turns to solid black. If I undestood correctly, this is not a bug of the TAdvGlowButton but TImageList.

Is there a way to fix this without using any 3rd party components?

I solved this by opening the project settings from Project Manager and checked Application -> Enable runtime themes. What kind of silly option is this? When would anyone want to not enable runtime themes?