testfor command not picking up items mofified with anvil

When using the command

/testfor @p {Inventory:[{id:"minecraft:diamond_pickaxe",tag:{ench:[

{id:32,lvl:5}

]}}]}

which output a redstone signal if a player has a diamond pickaxe with effeciency 5. The command will fail if such a pickaxe was obtained using an anvil and manual enchanting. However, this command will trigger if an identical pickaxe is created using the /give command, namely

/give @p minecraft:diamond_pickaxe 1 0 {ench:[

{id:32,lvl:5}

]}

It should be noted that when I later used the /give pick in an anvil (renamed it) and attemted the /testfor command again, it failed.