Under Shading:

Transparance: .5 (or halfway)
Edge Dropoff: 0.752

Under Color:

change it to black

This is the most important and difficult step. If not done right, the fire will not loor right.

Under Incandescence:

create 2 ramp controllers, and be sure they are both white. Put one in the middle, and one on the right end of the ramp.

Select the controller in the middle and set the values to :

H: 17
S: 0.8
V: 20

Now select the controller on the right side of the ramp, and set it's color values to:

H: 17
S: 0.8
V: 0

When you hit accept your ramp will magically change to that of the image shown here on the left.

Input Bias: 0.387