Why does Facebook hate my image?

I have a small 100x100 pixel image at this location: http://quoteth.is/images/bigquote.png

Facebook just hates this image for some reason. On my Facebook app page, when trying to upload it, it fails with no error message. When I use this image as the image link when posting to a user's wall, sometimes it appears, sometimes it doesn开发者_StackOverflow中文版't.

What could the reason be for Facebook not liking an image? I know they support PNGs, 100x100 is the size that they suggested. And it's a small file size. What else could it be?

Thanks!

You might want to try to lint your app url. http://developers.facebook.com/tools/lint/