I don't know who knew. All that seems clear is that the boy gave these IMs as proof against Foley years ago. (they're both republicans and so what?)
Drudge has an article (posted here on FR)
http://www.freerepublic.com/focus/f-news/1713788/posts
that proves that the technique of leaking this story was a total set up, supposedly to protect minors from sexual predators, but really a fake blog to leak this story 'innocently.'
We knew about the fake blog, days ago. I haven't seen any information about the kid turning over the IMs years ago. The only claim of having made a report, years ago was by Kirk Fordham, the former staffer for Foley. His word is extremely doubtful, since he is also gay and was being pressured by the same rabid gay activists that set up the fake blog.