The cache thing is important. Copies of your blog or site pages can remain on Google "forever", even if you have deleted them from your blog or site, and interfere with your HubPage Hub status.
It is probably too late for existing pages, but on all new pages, make sure you have, in the header...
meta name="robots" content="noarchive"
meta name="googlebot" content="noarchive"
There may be other stuff in those lines, just add the above content portions.
You know, of course, to put angle brackets around each line (can't show them here as that would attempt make this comment have HTML which is not permitted by HubPages).
The only disadvantage of not letting Google archive pages is that if your server goes down, a searcher will not find your pages during that (usually) short time.