View EXIF data of the latest sample images posted by Ned Bunnell:-

http://nedbunnell.blogspot.com/2009/06/da-18-55mm-wr-lens.html

He used the kit lens DA18-55 WR.

All exposures were made with Centre-Weighted Average metering but all images
required an exposure compensation value of +1.0 or +1.3EV.

Is that the K-7 still underexposing by that much? Do note that some of the
scenes/subjects might of a higher reflectance, but I'm afraid not by that much.

In addition, this is exactly WDC says about the K-7 - underexposure:-

http://www.whatdigitalcamera.com/equipment/digitalslr/1203/6/Pentax-K-7-DSLR-ful\
l-review.html

Despite that their review is not quite professionally made for many parts - but
it seems that they were really annoyed by the underexposure behaviour of the
K-7.