Thanks for the reply. I actually have authorship markup on the thread pages. I don't see the problem where an author, like myself, is linked to my Google account.
The problem seems to be occurring on thin(er) content thread pages that previously were appearing on serps. I can't figure out why they were dropped. It makes no sense that sites that have then copied that same content are coming up in results instead.
I have since done a small redesign and cleaned up a lot of erroneous code - mainly extra css and unnecessary js menus - but that hasn't helped.
One thing I did just realize is that the one site copying my content is also pushing to friendfeed. Interesting. I'll have to look more into pubsubhubbub.