Sand - 2:31 pm on Sep 14, 2012 (gmt 0)

Are there two or more sets of results that are being tested or is this the usual dancing?

It looks that way. For a couple hours yesterday afternoon, I was hitting a data center(s?) that didn't have anything I'd published in the last week in the index. The content in question was indexed previously.

Fast forward a couple hours, and the results looked up to date again. I had the suspicion that they were maybe testing a week old historical result set with a new one. Or who knows, maybe they just had some technical troubles and did what they had to keep things running.