I just returned from a weekend trip and my Panasonic "waterproof to 40'" camera did not survive. There is water behind the lens, even though the battery compartment seems dry. Yes, the door was closed and locked, yes, the seal was clean, and no, I didn't take it below 40'. In fact, it stayed at the surface with me during a few swims. Of course, I had owned it for 2 years and the warranty was 1 year.
I just purchased the new Pentax (I've had good luck with the previous Pentax cameras I've owned - both broke but both entirely my fault and under conditions that would break most things). It looks like a children's toy, but hopefully it will hold up to field conditions. I'll let you know how this one works out.