Hi, I'm Steve from Arkansas. I have a John Deere L120 48" rider. Since the beginning my rider has been cuting uneven. My dealer says it is due to the grass(weeds) I am cutting. To cut the grass I have to go forward and then reverse. If I cut two forward passes it will still be uneven. I have had the blades replaced and also sharpened. This made no difference. I had the dealer check for the deck being level and he says it is. Is there anything else I can check out to possibly correct the problem?