/summon Zombie ~ ~1 ~ {Equipment:[{id:stone_sword,Count:1},{id:leather_chestplate},{id:leather_leggings},{id:leather_boots},{id:skull,Damage:3,tag:{SkullOwner:MHF_Villager}}],DropChances:[0.5F,0.0F,0.0F,0.0F,0.0F]}

This command should bring a mob in with a custom player head of the villager. I have used the give command to generate a a placeable head but when i use summon the head comes out looking like the default. My first thought was maybe I was not online, but I use the cactus head for decoration and it was loaded correctly.

has the tag for skull owner changed when summoning?