It appears that a reindex has taken place very recently. Yesterday I did a search on my topic and found 219,000 results and today I ran the same search and found google report "around 308,000 sites". Rankings were also shuffled a bit between the original 219,000 and the 308,000, but they seem to have settled down now. I guess I caught them reindexing at that particular moment. BTW, I am 11 hours ahead of the east coast and so I tend to spot these changes when most of you are sleeping.