Compatibility with Co-authors plus

Hi!
I just wanted to ask for some advise on how to get this widget to work with the plugin Co-Authors Plus (http://wordpress.org/plugins/co-authors-plus/)

For some reason although that plugin works for the admin and the pages it doesn’t affect the Authors widget. Any suggestions on how to attack this problem?

Thanks!

http://wordpress.org/plugins/authors/