I'm one of the reasons there was an AD: please don't throw anything at me!!
Several years ago (when I first purchased my plane), I was having some cylinders on my Bonanza topped. The A&P (who I have not used sense) put ECIs on (contrary to my instructions) and after reassymbling the engine, there was a loud clicking noise that varied with RPM. He disassymbled and reassymbled the cylinders again--same problem. To make a long story short, the ECIs were made incorrectly and on the down stroke, hit the top of my crank shaft. Upon questioning the A&P, we found the cylinders were out of spec. Of course, he didn't check them before putting them in. I told some folks about the problem when it was occurring (before we discovered what the actual problem was). After the fix, a firm that I greatly respect called me back to follow up and find out what happened. Turned out, they had been hearing other stories about the same issue. Some FAA reps had also been hearing of problems and called them to see what they know. Anyway, it wasn't fun for the A&P or me. Plane was down several months. Other components were damaged, etc. As they say in Italian American, it was ) a biga messa!!
Best,
Dave