Smoke lighting is incorrect. Light on the smoke sprites appears to be coming from below, while light on every other surface comes from above (sun/sky). You can clearly see the discrepancy here:
http://i.imgur.com/jawRk.jpgThe smoke graphic looks correct, the smoke is darker at the bottom and brighter at the top where the sun would shine on it, so I'm guessing it's rotated incorrectly in the code.
base/pics/sfx/smoke_00.png