To clarify: that "dataType" param is part of jQuery's $.ajax function, which I believe handles xml, but might require some massaging.
I think your JSON issues might be caused because your JSON is not JSONP, which requires a ?callback=foobar parameter. jQuery is hiding some of this magic:
dataType: "jsonp",
is functionally equivalent to:
dataType: "json",
The "Error calling method on NPObject" was an exception from the VHX megaplaya, but like Casey pointed out it was caused by the malformed JSON. We'll add more informative debugging to the player.
-jamiew