Originally posted by 2351HD Before anybody decides to question my knowledge, I have been using a 645d and 646z with great success for years,
I think almost everyone else with the k-1 has been ecstatic over the great auto-focus, so your experience is clearly an exception. Whether that is due to a faulty camera, camera settings or your not being used to small DSLRs remains to be seen.
The obvious thing to check is what focus mode your are in. If you have it in AF.S and spot then your focus should be repeatable, mine certainly is. If however you are using Auto multi-point or Select multi-point then the camera has a number of focus points to use and will select the one it thinks best, which in many situations will not be the same one as the last time due to changing lighting, very slight movement of the camera and so on.
So to see if the camera is faulty, put it in AF.S and spot (single point) mode. Put it on a tripod and test the focus, it should always give the same result. If it is still giving inconsistent results I would suggest returning it as defective as this is not normal behavior.