How do I fix a broken Gravatar?

My Gravatar has become broken after activating & de-activating various Avatar-related plugins.

When logging into my WordPress website with an email address that matches my Gravatar account, my gravatar remains broken when I leave comments. However the dashboard view shows that my user name has an assigned avatar.

An example of the broken Avatar can be viewed here, a comment left on my own website:
http://beautyswatch.com/2011/10/clinique-mini-long-last-gloss-wear-spf-15-pink-ribbon/

Any help would be appreciated.