Not wishing to sound derogatory or superior, but isn't it amazing how as soon as we go through a bad patch we blame or 'out' the gun? It certainly seems as though it is human nature not to correctly identify the real cause.
I have a friend who has a Miroku in his cabinet that served him very well and it was used to make him an AAA class shot.
Subsequently he progressed? to Perazzi, Kreighoff, and now Blaser, but his shooting continues to deteriorate.
A few have suggested that he gives the Miroku an airing, but he refuses.
I asked him why not ? The answer was " Because I can afford better."
Now let us clarify something, I love Miroku, but own many other makes.
Recently I decided to treat myself so I bought a new Perazzi and then I bought another Kreighoff.
The Kreighoff I shot it and shot it and shot it. Despite tinkering and messing about with it I cannot for the life of me shoot it, despite help and advice from some very wonderful people I have to accept that maybe Kreighoff is not for me.
I know many people who cannot adapt very well to Browning's after learning to shoot with Beretta's or shallow action Italian guns or vice versa.
Shaun commented in another post that he feels he is missing a lot of clays over the top, I doubt that a higher comb will assist that malady unless of course his issue has nothing to do with site picture and has more to do with style and method.
One thing is for sure we will not cure it via the internet.
If something breaks or is broken go back to basics, retrace your steps.
