Redmine

When I tried to get data via Rest API with json formatting,
I got an error message saying "Uncaught SyntaxError: Unexpected token :" with Chrome 18, jQuery 1.7.2.

Here is the javascript code :

$(function() {
    $.ajax({
        type : 'GET',
        url : "http://www.redmine.org/trackers.json",
        success : function(data) {
            alert(data);
        },
        dataType : 'jsonp'
    });
});

But the confusing thing is that the response of the API seems to be valid...

http://www.redmine.org/trackers.json

Then, I tired to call Wikipedia API in the same javascript code,
This was successfully done.

$(function() {
    $.ajax({
        type : 'GET',
        url : "en.wikipedia.org/w/api.php?action=query&titles=redmine&prop=info&redirects=&format=json",
        success : function(data) {
            alert(data);
        },
        dataType : 'jsonp'
    });
});