http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=37539069
So..!? Well, I have no more to say!! >:-( Now, it seems that it is Not a Quality Issue anymore, but just a latent design issue and/or manufacturing defect!
To verify whether this "sensor" problem of the K-5 has been resolved and completely eliminated or not, I've just checked the PF's "serial number database" of the K-5, it can be seen that the latest s/n and units are still affected! >:-[ E.g., see:-
http://www.pentaxforums.com/forums/pentax-serial-number-database/?do=viewserials&id=133&sort=&page=4
Related:-
Report of Re-appeared UFOs with Repaired/Replaced K-5 Unit! :-o
LiveView of the K-5 Creates UFOs / Pearls on Sensor?
K-5 Serial Numbers and Issues Summary