We all know of the problems with stop down metering with the K10D, It doesn't work. The only way to deal with a quirk of a camera is to find another way of accurately metering. Start with what we know, most lenses appear to meter properly fully open, so if you want to meter for example f8 with a SMC M 1:2.8mm, open the aperture fully(f2., hit the green button to meter, shut down to f8(5 half stops/clicks) and with the EV steps set to 1/2 EV in the menu, increase the shutter speed by 5 clicks. f11 would be 7 clicks etc. Bob's yer proverbial.