Possible duplicates?

Is it possible that this [great] plugin is creating duplicates? When a search is performed (e.g. brochure) at my site http://www.whatsthebigidea.com, there are duplicate posts that appear. For instance, these are the same posts, just different versions: http://www.whatsthebigidea.com/27-revision-31.html and http://www.whatsthebigidea.com/brochure-design.html. I manually deleted all post revisions via DELETE FROM wp_posts WHERE post_type = “revision”; though http://www.whatsthebigidea.com/27-revision-31.html remains. Any ideas? Thanks for a very useful and time-saving plugin.

http://wordpress.org/extend/plugins/convert-post-types/