yes well your talking about the picture itself. That has nothing to do with Photopost to my knowledge.
The photo is processed with Imagemagick and GD2 so obviously one of those server image processor has a problem with your gif image. Maybe it is the transparency I cant say since those two programs would be supported by their authors.
http://imagemagick.net/script/index.php http://www.boutell.com/gd/
Those are the sites for those programs which are server programs. My suggestion to you is upload a jpg and a regular gif. If they work and it is this transparent gifs of yours there is your issue. I know for a fact no image processor is going to properly process an animated gif correctly. Maybe your issue is the same because you can not process a multi layered image with an image processor.