g1smd - 12:29 am on Feb 4, 2012 (gmt 0)

The Preview came with a blurb saying something about showing a cached version. This kinda implies that there also exist non-cached Previews.

What I don't get is that sometimes the Preview is quite stale perhaps days or more old with a much newer version of the same page viewable in the normal Google cache, while other times the Preview is very new but the cache copy is days or more old.