PNG files not maintaining transparency when uploaded with DFP2
I am using DFP2. I have set up an upload and set the file format to "Format: Keep existing format". However, if I upload a PNG file with a transparent background, the image ends up flattened with a black background in place of the transparent area.
I also tried "Convert to PNG" just to see what would happened. Same result.
How can I get PNG images to maintain their transparency when uploaded through DFP?