为什么我在Delphi 2009功能区中使用的透明图像在运行时不透明？

I just played around with the new Delphi 2009 ribbon, added a few pages, groups and actionclients (large buttons) to it. I created some transparent 32x32px PNGs in Photoshop and put them into a TImageList (set to cd32bit). I added this list to the Actionmanager's Images property, to show them on the buttons. At designtime the icons in the ribbon look just fine, but when compiling and starting the app they have a black background. Any idea what causes this and how I can fix this? I do not want to create the images with the ribbon color as background, because I cannot switch to another colorset of the ribbon then.I just played around with the new Delphi 2009 r