First of all, my profile picture on Programmers SE has changed by itself. If I recall correctly, the moment I clicked on the edit link, or when I made a change in one of the fields (not sure), the picture just changed by itself to what appeared to be Identicon.
On other sites, if I try to change my profile picture, I have Gravatar and Identicon options. As far as I can tell, only on Programmers SE, I don't have a Gravatar option, only Identicon. I'd like to use Gravatar on this site just like the others. This was working fine until a few days ago when I made a completely unrelated change to my profile.