BusterPunk - 2014-06-29

Hello,
I implemented some remote control features for my Tv (Philips 42PFL3218K) using the Jointspace JSON Api. Everything works fine with one exception: I can't set the the current source. Following the API documentation the syntax should be sending {"id": "hdmi1"} to [ip]/1/sources/current.
Doing this I get
400 [<html><head>Bad Request</head><body>Bad Request</body></html>]
All other commands (eg. key, send/get volume) works fine.

Any ideas what to change or is the docu wrong?