I finally figured it out. Your bushing that the spring rides in is probably not in all the way. I was wrong about not enough ledge space on the center threaded cylinder. Take the thumb studs off (use 2 T6) and also take the rotating stop pin spacer out. There should not be much space on either side of the blade where it pivots,but I'm guessing on yours there is. Only the copper bushing and about the same thickness of that bushing that holds the spring should be visible on either side of the knife. Once the thumbstuds are off and the space pin out, have the blade go beyond it's normal stop, that will get your spring bushing realigned back into the recess of the blade.
When you put the blade back in, the blade needs to be placed on top of the spring thing at the angle where it naturally stops (beyond the normal stopping point). Look how the spring engages the machined recess in the blade and youll see what I mean. Sometimes the blade likes to come unaligned from the spring bushing when you put the blade back on, if that happens, the blade wont stay closed and you will be able to see the spring bushing between the liners and you will have that pivot screw trouble again.