I'm having a problem that I cannot solve. Some of my Gravatars doesn't show. Look for example on this page: http://slipstreamlongboards.com/quiver2013/platypus-2013/
All I'm seeing when I enter the URL to the Gravatar image manually to my web browser is:
The type of image you are trying to process is not allowed
Why doesn't it show?
It is definitely a theme problem but I cannot find the problem in the theme.