Screw pics

I've been asked to post pictures of the screws that have been the root of all this, so here you are.  You'll see that they're pretty small, somewhat inconsequential items.

The one on the left is the original grub screw and the one on the right is the replacement.  You can see why to the untrained eye it might be difficult to believe that the new one would be suitable, but when you look below, you can see the size of the recess that it fills. 

Like I've said before, almost as if it was designed that way.