The lens is this:
I bought it a few months ago and used it successfully on my K1000. More recently, I modified it to remove the 'Rikoh Pin'. Once again, it seemed to function fine on the K1000.
When I put it on my K-x, it is not recognized as an auto aperture lens. As far as I can tell, the aperture ring is fully locked in the 'A' position. Also, the diaphragm arm moves freely and rotates fully to a mechanical stop.
Either I'm not doing something correctly, or something is physically out of alignment with the lens. How is an "auto aperture" lens detected by the camera, anyway?
Thanks in advance for your consideration.