This plugin works fine: when I archive list by author, the list is labelled as being that of the display name.
Here's where it doesn't work:
I use Photosmash Galleries (http://wordpress.org/extend/plugins/photosmash-galleries/).
In this case, when the Photosmash Galleries plugin is activated, the archive listing is labelled under the actual username (ie no longer the display name).
Not being a coder, not sure what to do. I suspect I need to tweak this plugin (not Photosmash) so that the display name shows again when I'm archive listing by author.