I have a new 54" deck craftsman that came with a mulch kit. I prefer to use it because it don't leave lines in my yard, and it give me a very nice grass look. However whenever I cut with it on, it leaves a lump of cut grass when I stop at. I'm forced to ride to the rear of the house or out to the street before I can stop just to let it dump this huge chunk of grass. So I have to remove the mulch cover and let it shut out the side but then I'm left with ugly lines of cut grass. If it's suppose to drop back down on the grass what am I doing wrong? I've tried it on all type of speeds. I cut when the grasss is dry.