diberry - 3:09 pm on Feb 9, 2013 (gmt 0)
Does Penguin "penalize" a particular search query but not others?
It seemed to in my case - certain queries and certain words within queries. Of course, it can be hard to determine which of the eleventy billion "quality updates" Google makes each week is "the one" that had a certain effect you're observing. I've made a lot of other non-Penguin-related changes on my Penguinized site since Penguin, and Google hasn't reacted well to all of them (and I don't care).