Author Image plugin uninstall problems

I installed the author image plugin and discovered it did not meet my needs — at least not without code modifications. (The avatar for the author for which I tried to use the plugin showed up blank.)

So I deactivated it and uninstalled it.
However, the author still shows up blank, even though I have avatars enabled and am using the “Identicon” as a default image.

I checked the page source (preview), and the avatar-related section looks the same as for authors for whom the avatars do show up.

I checked the database tables for users, and this user looks the same as all others.

I want to know what I can do to restore normal function for this user — i.e. how I can get the normal avatars/gravatars to show up.

What could the plugin have changed that is creating this problem?

(Yes, I have flushed my browser cache, used different browsers, etc.)

Please help!