The mobs do not burn on slabs.

[ENGLISH]
Sorry for my bad English, I am Argentinian.

I noticed a bug with the mobs, they do not burn on slabs being unless they (the mob) touch a nearby block of the total height of one block.

This text is translated with google translator.

[SPANISH]
Noté un bug con los mobs, éstos no se queman al estar sobre losas a menos que éstos (los mobs) toquen algún bloque cercano de la altura total de 1 bloque.