Ronald just updated Ajax Edit Comments to fix the really troublesome IE bug where the window just refused to close. You can update it from within WP-Admin directly or download it from the repository.
Ajax Edit Comments allows users and admins to edit comments on a post. Users can edit their own comments for a limited time, while admins can edit all comments.
The plugin has been tested on WordPress 2.8.5 as well. I have it running out here. If you notice any bugs, please report the same in the forum.