These days, the "Stains" reports of the K-5 now appear endlessly, see what this frustrated K-5 user in the Middle East complains, who is really pissed off:-
http://forums.dpreview.com/forums/read.asp?forum=1036&message=37111740
I do really feel for him, very very much indeed. Someone in the thread who've replied emphasizes that as long as Pentax honours a replacement under the warranty, it is "just a non-issue". The victim replies in the thread that it is not easy for him to get another replacement, as the stock is rather limited at his country, and also that the dealer may not honour the replacement at the end. But then other stupid Pentax fanboys immediately jumped on him for saying that it's all his fault for not checking the return policy before he bought, that IMHO is rather plain stupid and the real utmost stupid saying afterall! >:-(
So, do you think and do you know, even Pentax or her agents/dealers over the world do all honour the warranty and offer for the free replacement eventually, could the problem be resolved? It is not even mentioned about all the troubles and time or even money loss, including that for fighting for a replacement and the subsequent shipping and arrangement etc. as well as the time wasted for those troubles as well as the time lost for not having a new DSLR body for use and taking photos - which is what all the new K-5 users and Pentax supporters bought this new model at the first time at a premium price original intended for!!
Okay, to answer back the question. Here is the showcase of the first K-5 user whom I first seen for reporting the issue, back to early November. After prolonged "fighting" and struggling with the local Pentax sole Agent and his shop, he finally got his another brand new replacement unit for after almost a month. Previously, he reported that his new unit was fine (as it seemed to be) when he first got his replacement unit, but now he has just reported today that his new unit has started to have the *same* problem appeared! :-o As previously, he also posts a photo taken with yet his another replaced K-5 for showing the issue.
So, at the end of the day, this issue seems to be a real issue which affects many K-5 units as reported widely, even if not all. Do note that some users may not notice the problem unless they shoot with small apertures and check more carefully. All in all, I think Pentax/Hoya should issue a product re-call, which they have never done that before anyway, but Canon and Nikon did for other major issues of their products happened and confirmed before, in the big contrast.
As for the very possible cause of the issue, this Canon published service notice tells it all! (My special thanks to OGL for providing the information of this! :-))
http://canoncanada.custhelp.com/app/answers/detail/a_id/12944/~/service-notice%3A-eos-1d-mark-iii%2Feos-1ds-mark-iii%3A-oil-spots-on-lpf-surface
Okay, Pentax, or, you should be called Hoya, it's your take now! Still waiting? Want to hide around? Do not want to respond and just know to fix the issue secretly at your side as far as you can? Really? Yet once again??
If this most unfortunate behaviour of Hoya does happen again for this case, Hoya, I dare to tell you, you are the one who hurts yourself most for doing your business better! Originally, you could have been able to sell more of your products but since there is and will be no reaction, the sales hurt deeply - but by your ownself! >:-[ As time goes by, the reputation of your *brand* is trashed and Pentax dies. If it really happens, Hoya, you're the real culprit! History will record that! >>:-\
Update (12-9):-
1. The stain reports have never ended, an Australian user posted his photo that clearly showing the problem:-
http://forums.dpreview.com/forums/read.asp?forum=1036&message=37130900
Yet, here is another posted real world photo posted by a Hong Kong user:-
http://www.dchome.net/viewthread.php?tid=949406&page=37#pid11334257
By looking at all those affected photos, it seems that there is a chain of circular spots in a line across the sensor. And, most of them are near the centre. So, the cause of these may not be the oil splitting as in the case of Canon 1D3, but possibly other manufacturing issues.
2. The first K-5 user who found and reported the problem has posted the serial numbers of his original K-5 and newly replaced unit, which is yet still defective. The s/n begins with 3827 for the old one and the new one is 3877.
3. Yet another victim who has lately reported about his case writes that he has checked four different K-5 units so far, two s/n begin with 38XX and another two begin with 39XX. But he got no luck! So, as we can see, the problem persists and the latest batch of the production K-5 units are still affected! :-[
4. Now, the HK K-5 users and Pentaxians have created a name of this issue: "The K-5 UFO Incident and Phenomenon". They have started a Petition to Hoya at the DCHome.net Pentax forum. Let's see if Hoya will respond, but my bet is Possibly Not, as we learnt from the SDM failure case, the 1,000+ Pentaxians in a Petition are just got completely ignored!
Last Report About the Issue:-
"Stains" on K-5 Sensors, the Story Continues..