I'm going to go a slightly different way. Set your camera to use Center Point AF only. That way what you are focusing on in the middle of the screen, or rather what you Think you are focusing on, is in fact your focal point. I don't know how the Kx is shipped but regardless, there is no Visible point confirmation in the viewfinder. Therefore, you may Not be focusing on what you Think you are. The AF system on Pentax's latest cameras is actually pretty good. Not the best perhaps, but good nonetheless.
With respect to the Live View, I agree with the others. Even on the K7 it's fun to play with (sometimes), but it is Painfully slow. For some reason (on the K7 anyway) the focus system insists on going from one extreme to the other, regardless of lens, before locking on focus. If you're going to use LV, you are best off going manual focus.
If that fails, return the camera. No point in being miserable with it.
Edit: Sorry kytra, didn't read your post before making mine. Romanians must think somewhat alike