I installed WP-Gravatar, it didn't work (my custom gravatar wasn't displaying), so I uninstalled and now I'm left with empty boxes where the avatars are supposed to go.
It's hard to explain so please take a look here: http://www.blog.gnobrand.com/busdriver-me-time-with-the-pulmonary-palimpsest-video/
I'd appreciate it if someone can help me get rid of those boxes.