That's odd... Could you have a go at adding a 'Content-Length' header?
There are a few examples of POSTing data on the IoT services page: http://www.espruino.com/IoT+Services
and you could have a go at modifying one of those?
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
That's odd... Could you have a go at adding a 'Content-Length' header?
There are a few examples of POSTing data on the IoT services page: http://www.espruino.com/IoT+Services
and you could have a go at modifying one of those?