URGENT - imgIContainer problem with PNG

Hi,
In my embedding application (Windows, C++) I'm using
imgILoader::LoadImage to fetch images. I retrieve the image from the
imgIRequest using imgIContainer::EnsureCleanFrame. The problem is that
I can only get JPG images, PNG ones come out black.
Any idea?
I would appreciate any help, this is quite urgent.

Thanks,
yakobom