I have not had the problem with all the grain in the center, generally they will pile on the righthand side. I would guess you probably have the old, overloading and sluffing problem. We put on one of the Hilco fan kits that Marvin Gordon sells. It helped tremendously. Cleaner samples w_ less returns and much more even feeding on the shoe. A set of cover plates is also a good investment. Put disrupters in and it really just made the shoe overload problem worse. More stuff winds up on the shoe than without them and this is not necessarily a good thing. I look forward to running the machine a whole season with the mods in as we just had it in at the end of last season. Chads