When I store transparent images with shadows as .png I have filled areas instead of soft edges. It seems like it is a saving/compression or whatever problem because the .psd is in photoshop really fine and the same .psd worked for a transparent when he created the transparent .png.
This is how it looks as .png: http://puu.sh/gZdrh/8b8fc16424.jpg
This is how it looks in photoshop (red background):
What is causing this problem? It's a RGB / 8bit .psd