Reno - 10:55 pm on Feb 28, 2011 (gmt 0)
Sites that show improvement rarely hurry to post the good news anywhere.
As you & I & others have said, when a system is wholly complex then a small tweak can have massive repercussions. And that's who we're hearing from here ~ professional webmasters who know what they're talking about are seeing their sites getting hit hard, and they're/we're at a loss to explain the reasons. I'm sorry to say it's going to be like this from now on, because Google will never stop adding new spice to the soup. They serve it with a "take it or leave it" attitude, and so we come to Webmaster World, hold our collective noses, and take it.