Why is my Animate alone broken?

Using the Raphael.js I have made a circle and a path, all I wanted to do was make the ci开发者_Python百科rcle animate alone the path, as if the center of the circle went along the line.

http://jsfiddle.net/rEJNJ/3/

Can anyone offer some advice

window.onload = function () {
            var paper = Raphael("canvas", 640, 480);
            var c = paper.circle(90, 90, 40);
                c.attr({fill: "blue"});
            var p = paper.path("M150,380 C150,360 50,250 220,90").attr({stroke: "#ff0000"});

            c.animateAlong(p, 4000, true);
        };

The animation works if you create your circle with the same X/Y coordinates as the beginning of the path:

http://jsfiddle.net/rEJNJ/4/

window.onload = function () {
    var paper = Raphael("canvas", 640, 480);
    var c = paper.circle(150, 380, 40).attr({fill: "blue"});
    var p = paper.path("M150,380 C150,360 50,250 220,90").attr({stroke: "#ff0000"});
    c.animateAlong(p, 4000, true);
};

Take a look at this post for some insight as to why: SVG animation along path with Raphael