Rotation around center of mass is weird.

[Chazrox]

Im drawing a star and trying to rotate it around its center of mass without including the gradient in the rotation. At lower point counts its alot more obvious whats going on. For some reason at higher point counts its stable. hmmmm

If anyone else wants to give it a go.. Thank you!

MyKnobLaf.registerFunction("drawRotarySlider", function(g, obj)
{
    var a = obj.area;
    var range = obj.max - obj.min;
    var stableSize = a[2] * (1.0 - 2.0 * 0.15);
    var ox = a[0] + (a[2] - stableSize) / 2;
    var oy = a[1] + (a[2] - stableSize) / 2;
    var cx = ox + stableSize / 2;
    var cy = oy + stableSize / 2;
    var sw = stableSize / 200.0;
    var startOffset = 2.5;
    var totalSweep = 2.0 * startOffset;
    var endOffset = -startOffset + totalSweep * (obj.value - obj.min) / range;

    // ============ COLOUR CONTROL ============
    // -- Star Body 3 --
    var cStarBody3Top = 0xff888888;
    var cStarBody3Bot = 0xff333333;

    // -- starBody3 --
    var starBody3Size = stableSize * 0.8;
    var starBody3Star = Content.createPath();
    starBody3Star.addStar(
        [0.5, 0.5],
        3,
        0.42,
        0.5,
        endOffset
    );
    starBody3Star.roundCorners(1);
    var starBody3Area = [cx - starBody3Size * 0.5, cy - starBody3Size * 0.5, starBody3Size, starBody3Size];
    g.setGradientFill([cStarBody3Top, cx, cy - starBody3Size * 0.5 + starBody3Size * 0.5 - starBody3Size * 0.5, cStarBody3Bot, cx, cy + starBody3Size * 0.5 + starBody3Size * 0.5 - starBody3Size * 0.5, false]);
    g.fillPath(starBody3Star, starBody3Area);

});

I Cant figure out why the shape warbles when