Do you put water in yours? How does it do with just making "black fat" smoke? I let my water pan go dry one year in my old farkin' brinkman and I got a black tire fire smoke from the fat. (could also be because of the crap smoker) I'm betting that is why but I was wondering when you said you use this to collect drippings.
Ever think of letting the drippings go down the ash pan handle and gather in the ash? might make it messy but nothing a hose couldn't take care of. It would eliminate the smoke problem I had (if you have ever had that).