JComments DAvatar plugin makes support of users´ avatars in the JComments component. You can use this plugin instead of JoomlaTune´s JComments Avatars plugin.
This plugin requires DAvatar content plugin, so you need it to be installed, enabled and configured.
You must decide which plugin you will use to show users´ avatars in comments: this one or JoomlaTune´s. Of course, you can install and enable both plugins, but only one will effect (last in the order). You must know, that this plugin needs more resources and generates more database queries. So why you can choose my plugin? Main reason is JFusion. DAvatar plugin works with any application, integrated via JFusion.