Can't /summon Zombie with item in 0 slot

When executing command:

/summon Zombie ~ ~ ~1 
{
Equipment:
[
	{id:268, Count:1},
	{id:309, Count:1},
	{id:308, Count:1},
	{id:307, Count:1},
	{id:306, Count:1}
]
}

appears Zombie in full iron armor but without any item in hands. Same problem with pigman, or any other item IDs in 0 slot. Works fine for Skeleton.