Google Weirdness

I was experimenting with Google for a bit, to see if I could retrieve comments left at this site via Google. What I've found is that most comments that I've tested cannot be found by Google, though they can often be pulled up by the Yahoo search engine.

However, I was able to find a couple of comments left at this site through Google, who knows why.

One very weird thing though was that I found one comment via Google (it was the top hit), and then later rechecked the same comment via Google-- and it was totally gone.

So there is some funny business with Google and particularly blog comments. I do not understand how a Googled link could disappear like that when re-Googled.