Yeah, I've had no problems at all with it. Works great for me.
But I'm aware that many people have had problems with it. Another issue is the little screw on the spring clip backing out causing the clip to jam in the camera.
Not good!
I don't really hear a click when it locks in. I just place the adapter in the opening, and give it a gentle twist until the clip clears the tab it locks on, and I feel a little resistance. When I mount the lens I don't crank down on them really hard either. Just gently snugged down enough that it will not back off while focusing or adjusting the aperture ring.
Eventually I'll look at getting the highly recommended genuine Pentax adapter, but for now this one works for me.
Glad you got it sorted out anyway.