User blog comment:Kirkburn/Technical Update: May 11, 2015/@comment-25039211-20150512160720/@comment-126761-20150513173937

It's the same issue, essentially - avatars are not updating as they should be, likely due to caching problems. I don't believe it is an issue with the avatars themselves - just the way we're displaying them (so it shouldn't require any changes from users).