Pentax have apologised for a batch of K-5 DSLRs that were shipped out with a stained image sensor. Cameras with this problem have produced images with spots that look similar to water drops when recorded under certain conditions.
The Pentax Imaging website says: "We deeply regret that the first shipment of our Pentax K-5 digital SLR camera included some products with a stained image sensor — a problem which we believe was caused during manufacturing — causing them to occasionally produce images with spots which look something like water drops, and which users cannot remove with ordinary cleaning methods.
We sincerely apologise for any trouble and inconvenience this problem may have caused. We also promise to do all we can to achieve the highest level of quality control in the future, and eliminate any worries our customers might have about our products. We sincerely appreciate your kind understanding and cooperation regarding this issue."
They also thanked Pentax customers for their patronage of Pentax products.
All K-5 owners who find their product has this problem will get their camera repaired for free at a Pentax service centre. Please contact the retailer you bought your camera from for more information.