http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=33243488
And the posted photo of the "separated" lens is linked:-

In fact, this is not the first time I see such a reported case. Last time I saw in a Chinese forum that a DA pancake lens was automatically self-separated into two pieces like this, exactly (the link of the post cannot be found now, though).
So, the durability and reliability of those super-thin Pentax pancake lenses are now in question. Is it horrible enough to see a lens to self-disassemble into two pieces like this? Really something unimaginable, I must say.
Update (10-20): One More Recent Adverse Report..
http://www.dchome.net/viewthread.php?tid=772742
(in Tradition Chinese)
The whole focusing assembly of his new DA 21 which purchased only one month ago has loosen and there is great play. The user questions about the "limited quality" of the limited lenses. Well, what to ask actually? Pentax has told us already! From the words "limited quality", it just means the quality is limited! ;-D
The sky is falling · 804 weeks ago
Actually in general I have the same sort of experience with my pentax stuff as you have, I do not like to care about my possessions I want to use them. And by me that means that all my lens hoods are loosing paint but gaining on dents. And the pentax stuff seems to withhold my carelessness so far. Maybe my lens just needed a break. And it had one! ..........................................
illdefined · 804 weeks ago
the real question is how many positive reports and reviews it will take for Rice to believe at least some of them are true.
Oodini · 804 weeks ago
illdefined · 804 weeks ago
RiceHigh 110p · 804 weeks ago
Somma · 804 weeks ago
Andrew · 804 weeks ago
RiceHigh 110p · 804 weeks ago
Tim · 803 weeks ago