Google Calendar API - how to add a calendar gadget along with event?

I'm trying to add a google calendar gadget along with an event. However, whenever I try and add a gadget along with an event, the google calendar API gives me an 'invalid value' error.

I'm using the event.insert protocol. If I send the request in without the gadget block, it works fine and adds an event. However, adding the gadget block throws an error.

{
 "location": "San Jose, CA",
 "description": "blah blah blah blah",
 "kind": "calendar#event",
 "start": {
  "dateTime": "2012-04-04T10:00:00.000-07:00"
 },
 "end": {
  "dateTime": "2012-04-04T10:00:00.000-07:00"
 },
 "gadget": {
  "iconLink": "http://www.thefreedictionary.com/favicon.ico",
  "link": "http://www.thefreedictionary.com/_/WoD/wod-module.xml",
  "title": "Word of the Day",
  "type": "application/x-google-gadgets+xml",
  "height": 136,
  "width": 300,
  "display": "icon"
 }
}

Does anyone know why this is occurring? I really need to find a way to insert images into the events I add to a google calendar. Thanks!

Solution

I too was faced with this problem. It seems to me that the the iconLink and link must be https for this to work.