When i insert raw wood in an burner inserter, then the coal disappears from the transport belt. The coal was not used by the inserter - the coal is terminated. I have saved the game on this point. You can download it here:
http://1drv.ms/19naMc2 (Ollo.zip)
You must only a 50er stack put in an burner inserter, and the coal disappears. It is reproductable.
I have made three screenshots, which you can see here:
http://1drv.ms/19naBNS
One screen displays the raw wood in the inserter, the two other pictures displays the disappearing coal. Its two pictures in a short amount of time - No coal to see behind the first inserter.
I hope, my english is understandable.

EDIT:
I forgot:
I play with the following Mods:
Dy Tech, F-Mod, Landfill, Treefarm and compression chests