@Bewenched and Browsee,
I am seeing word for word copies of some of my focused articles in my niche that are appearing on eHow ABOVE my article as well. No link backs. Here's a crazy example: One of my entertaining pieces, full of opinions and tips is a "how to". It was actually linked to by CNN! It has since been plagiarized and rewritten and now appears on an EHow article above my post, when it was not there before! The plagiarized piece is a 1/3 of my huge post. And it has a few minor changes here and there.
On another example, I found a site called "gulf news" that published one of my long, in-depth articles. There's been some minor syndication of my work through blogburst in the past. But today, all my new work is taken by small scraper sites and aggregate sites.
I have shut down my RSS feed to provide excerpts but I still am finding scrapers continuing to publish my new posts in full without links. Their sites are very light, with no links in or out. They only link to their own pages. My site has monetization elements and with links that are inbound and outbound. Plus lots and lots of comments on those posts. If anything, my blog shares a similar profile to CultofMac, albeit much smaller and less visible (but a big name in its space).
Again, something tipped the balance here, a little too far perhaps. There may be certain quality factors in play, and duplication is one of them. But if it's my #1 problem, then even if I cleaned my site out, who knows if I will see any restoration of ranks? Once a scraper finds you, there may be no way to shake them off (as seen when I stopped publishing full RSS feeds... they're still doing it!).