I have upgraded to the bigger chip tray in my unit but it seems that every time i put in a tray of chips it only pours good smoke for approx 20 min or so. Is this normal? When it is smoking good I can look inside and it is very nice and hazy....Im smoking at 220 degrees. And it also seems that when a load of chips dies out It takes a long time for the new chips to take off....Am i doing something wrong? I pulled the chip tray inside the unit out approx a 1/4 inch and that seemed to produce alot more smoke inside the unit. Any advice would be great.Thanks-