Wow! What a firestorm THAT was! As it turns out I had a bed of coals that were blocking the holes on the side by about 4 inches ABOVE the holes. I'd never really had to clean out the box itself, just the chamber below. Put a new fuse in, cleaned out the fire box completely, started up as fresh fire, no more smoke coming out the back. I think I just starved the hell out of the rig. We'll see. For those of you who figgered, 'well dude, you're on your own.' Well, that's probably the best way to learn, I guess. Whew.