This is a serious bug. For example, I post a blog, then I don't like the address, so I go back and edit the blog post to edit the url. This is something WP allows, and is completely normal. So WP remembers the old url and therefore *both* urls go to the same location. That's built in to WP, but this Redirection plug-in breaks that!!
IMO this plug-in should be removed until this major error is fixed.