Hello,
Because some of my users use Email as their username in Joomla, I found if it's email as user name, the Avatar will link to user profile with error, maybe you can consifer the other way to link to the user profile.
The error linkage format is as following:

http://www.herbalnc.com/cjblog/user-profile/962-wang19700485@kimo.com

Thanks a lot.