[Senator]

Sounds like you may need to "tamp" a little more. And by "tamp" I don't necessarily mean tamping the ashes down (which you also should do by that way).

What I do when I want the surface to maintain an even heat/fire distribution is to very gently move the tamper around the surface (barely touching the ashes) while slowly puffing. This focuses the draft air on the unlit surface areas which draws the fire/heat. Essentially, you're directing the fire this way.

Best way I know of keeping an even light.

PS: If you're finding the fire only wants to go down the middle...place the tamper on the ashes in the middle of the bowl and lightly puff. By not allowing the fire in the middle of the bowl any air, it will force the outside of the bowl to light.