nfc hangs when querying the object

Whenever I try and query the nfc object it just hangs.

I'm using Espruino Wifi and have my setup code like this:

 I2C2.setup({scl:B10, sda:B3});
 var nfc = require("PN532").connect(I2C2);

That doesn't make anything hang.

But if I then try this

console.log(nfc.getVersion());

It just hangs. Doesn't matter what method I call on the nfc class, it just hangs straight away.

I've tried i2c1 as well and I seem the same behaviour.

Any ideas?