I updated my avatar at gravatar about 16 hours ago. It has not updated here yet.
This is what it should look like:
You can see what it actually looks like next to my post.
How long should I have to wait for the avatar to update?
I have cleared my cache, rebooted, logged in an out of EL&U and logged in and our of gravatar, none of these things worked.
The problem seems to be how gravatar cache the URLs. Semantically identical URLs give me different avatars.
I have posted at the WordPress support forum. I'll let you know if anything comes of it.