I just recently purchased a YS640 last week. I had some time yesterday to fire up the smoker and perform the initial burn off. The instruction say to burn at 350 degree's for an hour. After the hour was up I open the lid come to find a lot of ashy saw dust all over the grates and body of the smoker. he smoker came with 40 pounds of Lumber Jack oak pellets so that what I used. My concern is that the residue will end up all over my meat while im smoking. Does anyone else have this problem or is it just me. Any ideas on how to fix this problem so I does't happen again would be much appreciated