I have the following code:

var params = {};

params[opensocial.Activity.Field.TITLE] = "twit: "+tw.text;
var activity = opensocial.newActivity(params);

opensocial.requestCreateActivity(activity, opensocial.CreateActivityPriority?.HIGH, function() { });

And I am given an error when calling opensocial.newActivity():

A is undefined
[Break on this error] opensocial.newActivity=function(B,A){Atitle?=B;

But I've checked OpenSocial documentation, and several examples, and they all do like I currently do in my code.