Wow, thats the most detailed post of a problem I've seen. Thanks! In your owners book there is a distance setting that the front retarder drum needs to be away from the header plate. If this distance is too great, the chain cannot pick the material away from the header auger. This will cause the material to feed in slugs. When it feeds in slugs, the rock rotor cannot take it away fast enough and it can refeed. It is a seperate setting from the heighth distance. Next, I would make sure the feeder chain is at the proper tension. If it is too tight, the same problems can occur. It will not pull the green material up the feederhouse in a smoothe fasion due to the added drag of the material on the feederhouse bottom. I've seen some people have a problem with the chain and they take a link out and then just back off the tensioner to connect the chain. That does'nt work. It pulls the drum back way too far from the header. When the feeder plugs and you look inside, has any straw rapped on the drive shaft and sprocketsIJ If the sprockets and stripper plates have worn and material is rapping, it wil cause the chain to tighten and the rapped matrial will carry stuff over the top and refeed. Some times with the rock rotor being there it will only allow a small amount to rap and then clean until the next slug comes up. If your massy did'nt have any extra stone protection, and your area is fairly clean of rocks, (sounds like it may be if you're growing alfalfa) then remove the rock rotor system. The rock rotor can be a capacity limiter for sure in some conditions.