It could be the page was cached and then was dropped so now it is showing as not cached. At the time of the last pr update or more maybe the last snapshot for the update it was cached.
you guys talking about google cache? it has been ridiculously slow for google cache. I only got 108 backlinks using site:url command on google, but instead, I checked other domain backlinks tool, they gives more results than google does. Sounds interesting, isn't it!