http://www.amateurphotographer.co.uk/news/Pentax_investigates_K5_DSLR_sensor_contamination_news_304445.html
"'foreign matter' lies under the AA filter and 'cannot be cleaned off'."
"'We are investigating this as a matter of urgency.'"
Well, I am still awaiting the official statement from Pentax and Hoya anyway!