I'd assumed the OP meant Google's 404 page, with that characteristic "That's all we know". Matter of fact, he says so explicitly. Oops.
:: pause to contemplate the wild incongruity of google claiming ignorance on any point ::
You've been reading WebmasterWorld too long. You've grown used to material being cached and indexed before the page has time to refresh. For the rest of the world it takes longer ;)
But that still doesn't explain what google-- of all people!-- is doing, linking to a page that doesn't exist. Do they create the URL for the cache before creating the cache itself?