Turns out it was the same exact paper. Well, almost. The plagiarizers made two changes: of course they made themselves authors, and they added several citations to papers they had written (or plgarized?).
The saddest thing about all this is that each of the plagiarizers were themselves holders of doctorate degrees. These were not grad students who didn't know any better (although a grad student should know better), but full tenured professors!
I can't think of a better example of how the reward system in academia skews scientific progress.