Shaddows - 4:46 pm on Apr 26, 2013 (gmt 0)
Think about this from a Document Classification POV.
The Title element and H1 Tag are supposed to define what the document is about. You have just changed both.
You have also changed the prominence of a second keyword through content and tags.
In the abstract, that document looks NOTHING LIKE it used to. How it "looks" semantically in relation to upstream and downstream links, how it works with KW co-occurrence, all has changed at the same time.
Changing the Title element has never been a risk-free activity. When combined with a load of other SEO activity, in the current climate, I would expect a fair wait before the situation settles.
Best advice: DO NOT FIDDLE UNTIL IT STABILISES.