Your camera isn't defective. For EXIF information like lens information to be displayed, your image software needs to know how the information is recorded in the camera EXIF.
It seems the K-3 has introduced a few changes into the way camera and lens EXIF is written, so most EXIF reading sotware (Lightroom, Aperture etc included) will need to be updated to reflect those changes in order to read all the data recorded by the camera.
There's currently
a whole thread or two about it over at the other forum. Handily, the author of exiftool (Phil Harvey) is a participant in the thread over there and is aware of the K-3 changes. So an update to exiftool that is K-3 aware may be coming soon (v9.41?). Many downstream tools rely on exiftool so will probably inherit the changes, but others that don't will have to make their own modifications in order to properly read the EXIF in K-3 RAWs and JPGs.
The one tool at the moment that should have the ability to read all the camera EXIF would be Pentax Digital Camera Utility v5, included with the camera. How does that read and display your lens information?