Forum Moderators: open
The last change I made was to exchange our — in title-tag (like "Company name — the premier company of ...") with a normal "-".
We almost immediately jumped to #4. Now, I'm not 100% sure this was the cause of it, but I figure it's almost certain.
Suddenly this hype was gone and most likely google took action about that. (this was about 2 or 3 months ago I believe but you can search the google forum). I remember that those pages were suddenly completely gone out of the SERPS and ending up in the 2xx or 3xx regions.