User Levels and Roles

Based on your explanation of User Level/Role authority here:
http://codex.wordpress.org/Roles_and_Capabilities

It says:
Author Level – Somebody who can publish and manage their own posts.

Am I misunderstanding this?

I am running WP 2.1.2 on a webspace using Andreas09 Theme that allows me some leeway on modifying presentation code and colors.

I set a user to Author and want him to be able to edit his own post “and” his own comments. He is able to edit his own posts but not his comments. Setting him up to next level (Editor) allows him to modify/edit “everyone else’s as well”. That is not what I want.

Is there any way to allow Author mode to edit his/her own post, and comments, but not edit everyone elses’s.
Thanks.