[Plugin: Filter By Comments] Display new posts above commented posts

I’ve installed the plugin and now the post with the most recent comment appears first on my index. However, I would like it to be ordered by the most recent comment or post. ie. The most recent thing to be posted, whether it is a post or a comment on a post, that post should appear first. For example:

#1 Post-C (posted at 15:00, no comments)
#2 Post-A (posted at 12:00, most recent comment at 14:00)
#3 Post-B (posted at 13:00, no comments)

Post-A appears above Post-B because Post-A has a comment posted since the most recent thing in Post-B. Post-C appears above Post-A because it is more recent.

Currently, using this plugin they would appear like this:

#1 Post-A (posted at 12:00, most recent comment at 14:00)
#2 Post-C (posted at 15:00, no comments)
#3 Post-B (posted at 13:00, no comments)

Like this, a new post never gets to the top of the index unless it gets a comment.

http://wordpress.org/extend/plugins/filter-by-comments/