[Plugin: Sub Title Plus] Current version not compatible with WP 3.1.

Does anyone have a better solution than me downgrading from 3.1. to 3.0
so that I can add subtitles to my posts and pages under the post titles.
I saw a tutorial on http://www.clevercarrot.net/wordpress/how-to-add-subtitles-to-wordpress/

but it doesn’t seem to work for me.

Any ideas would be of help :)Thanks!