HermanMunster - 6:23 pm on May 22, 2012 (gmt 0)
Maybe you shouldn't have fixed the: "duplicate title tags and meta descriptions."
@Regular_Joe: I was thinking the same thing after the Penguin hit the fan, but Webmaster Tools was telling me that those were HTML errors that needed to be fixed to improve my visitors' experience. Why wouldn't I listen? Remember, I'm not optimizing my site, just cleaning it up.
The duplicate title tags occur in Wordpress due to pagination of multiple pages off the home page and category pages, etc. I used a plugin to add Page 1, Page 2, etc. to the end of the title tags, with no other change. It wasn't a total rewrite. There were a lot of those, but the duplicate descriptions were only on 4 static HTML pages that never ranked anyway, and that I don't really care about.
I also took care of some duplicate content issues that Wordpress creates by default. That never affected my rankings before to my knowledge, but that is what the pros were saying was necessary. All of these things are supposed to help but they had the opposite effect. That's what leads me to believe there is no one-size-fits-all answer.