freejung - 3:46 pm on Jun 25, 2010 (gmt 0)
Sometimes it seems to me that Google doesn't always like change, especially change that would normally be expected to increase your rankings. I've seen many cases where making significant changes to a page after it's been the same for a long time (including changes to the backlink profile) will cause the page to drop out of certain SERPs for a while. Generally if you're doing things right, which it sounds like you are, the page will return after a short hiatus, often with significantly improved rankings.
My opinion is that you should not do anything different. Continue to build the kind of quality, editorial links you're building, and eventually you will do quite well.