I'm still waiting on one from April, but I've gotten later orders (including one from June), been in touch with Club Bing, and I'm fairly certain it's not a flagging issue. The missing prize is "in que to be shipped".
I've gotten that. If you can manage to get a point or two, then quit that puzzle, the next one should be normal. At least that's how it worked for me...
Did anyone actually manage to read the sweepstakes rules? I clicked the link, which showed in my status bar as a part of the Sanford site, but ended up on a Rubbermaid page that had nothing to do with the sweepstakes.
The last blank email came just a few days before my last prize shipment, which came just a few days before the notice that it had been shipped. Hence the excitement on my part.