Is this plugin under new management now?
It seems to be; the previous maintainer was username "dartiss" (David Artiss); but now it's "Dark Designs", and this URL - http://wordpress.org/support/topic/the-current-state-of-transient-housekeeping - speaks in the 3rd person of "The original author of this plugin, David Artiss".
On the other hand, the profile page for "Dark Designs", http://profiles.wordpress.org/darkdesigns/, links to David Artiss's social networking pages and homepage (apart from a Twitter link to an account for a Daniel Artiss), which tends to suggest the two are the same person.
This is rather confusing! (I've got nothing at all against the ninja coding skills of dark aliens with dual identities, but I like to be reasonably strict about which plugins I trust, so the information is helpful).