UPDATE
Sorry to hear the latest group of reporters has also run into the problem. I wish we could really nail-down how wide-spread the problem is. I happen to think it's quite significant that in a month's time, we've accumulated 74 reports here in this thread.
Someone over at DPReview started a poll on how many people have had the mirror-flap problem - right now it stands at about 14%. Of course, just because someone hasn't had it yet, doesn't mean they won't run into it later... and that's the problem with this problem, isn't it? It's so unpredictable.
Last week, I finally left a negative review on Amazon.com. I held off doing it for a long time because I hoped, by now, Pentax would have resolved the issue.
And I've just sent my write-up about the issue for publication on another website. I had held off doing that for all the same reasons.
I would recommend some of you, if you are so inclined, go over to
Amazon.com and leave a review about your experiences. Until Pentax feels pressure about this, they aren't going to address the issue... and with the
recent post about the guy who just got his camera back from repair who told him they never heard of the issue, I think the time is well-passed for Pentax to start to feel some pressure.