CustomNameVisible doesnt work

I tried to name a Pig "Pedro", and that worked, but with the CustomNameVisible:1-tag it just showed the name if i look at the pig...
this commands shows the same in my minecraft:
summon Pig ~ ~1 ~

{CustomNameVisible:1,CustomName:"InsertNameHere"}

summon Pig ~ ~1 ~

{CustomName:"InsertNameHere"}

i hope you can tell me what to to that it will work
and again sorry for my bad englisch