A few notes regarding genuine vs. generic and removing of springs...
- The only reason to remove the spring is to prevent a generic 3rd-party adapter from becoming stuck on your camera
- The chances of a generic adapter becoming stuck is fairly high
- The genuine Pentax adapter does not get stuck and should not require removal of the spring
- The generic adapter is not worth the savings unless you want to convert your M42 lenses permanently to K-mount
- The safest way to use a "springless" adapter is to attach it permanently to the lens using Loktite and notch/drill the lens base to engage the retention pin from the camera body
Steve
P.S. As has been said many times before on this site...get the genuine adapter...