fire and smoke problem

Hi Folks

kindof a newbie here. Reading a few tutorials and trying to get my head around simulating fire and smoke.What I’m doing is based on this

http://www.miikahweb.com/en/tutorials/blenderfire

I go along with the tutorial and everything is fine and suddenly when I render my fire seems to be coming from multiple place while I only have one object emitting particles. It took a long time to track down what’s causing it but it appears to have to do with resizing the domain object. I had started out just using the default cube for my domain but after having a little success of course I wanted to enlarge it so the side are out of camera range. After resizing it how I want I get crazy results. I tried applying location, rotation, scale but this made things worse. Any idea how I solve this problem?
Blend attached

edit: don’t seem to be able to attach a file
try this

http://drobbins.net/smoke2.blend

hmm, now I see that if I simply scale the domain up, no problem
if I make it bigger by grabbing on of the faces in edit mode and stretching it, I have trouble