Extracted iPhone OS images showing as 0x0

when i try to download a image from my iPhone (Drop Pin Marker) through a FTP client the file always shows up on my desktop as width-0 height-0. It can be viewed on a internal file system viewer fine but when it gets to my desktop it has no size. Why is thi开发者_StackOverflow中文版s and how can I open these files?

If it's an image, the iphone does some interesting things with png's. It inverts some of the color channels somehow. Here's some info on it http://modmyi.com/wiki/index.php/Iphone_PNG_images