Originally posted by DSims It's the most plausible explanation I've heard yet for why some people are suddenly having trouble with the WR failing on their K-3s (which are too new to have the seals worn out) when they never had such problems on their K-5 or K-5 II's. It based on other threads I've read on this forum; it's not something I'm making up.
The other possibility is that Ricoh isn't making them as well from the factory - I certainly hope this isn't the case. Naturally it's possible that this is mere coincidence, but that's unlikely because people tend to repeat their behavior, especially when something's worked fine in the past. So even if the number of reports so far is small, there's a good likelihood it's an actual problem, because their new K-3s aren't handling the weather as well as their older K-5s did (and still do).
FWIW, I own a K5II and I did have a WR failure. I was on a 2-hour hike during which there was light (but steady) rain which did make us quite wet. I was using the 18-55WR exclusively. At some point, the camera started to freak out - the mirror flipped excessively on its own, some black images were generated, the shutter button stopped responding reliably, and the power dial did not shut down the camera. These are all the typical symptoms of WR failure I've seen in other people's posts - not exclusive to the K-3. Back at the hotel, I removed the battery, card, and lens, and dried the camera for several hours with all doors open. Luckily, the camera worked properly afterwards.
Needless to say, I was quite dissapointed. These were in no way extreme conditions, and well within what Pentax/Ricoh advertise the typical uses (and advantages) of their WR DSLRs.
So I grudgingly readjusted my expectations. I no longer trust the WR being more than an additional layer of protection. On the occasional water splash, I know I don't need to panic (which is nice), but I no longer expose my camera to rain.
In summary, I believe that there is a weakness in the WR sealing somewhere around the shutter or battery. I suspect that this weakness is common to most or all models, spanning both K-5s and K-3s and possibly others as well.