We have seen the same thing. The re-append was the solution we documented a the only work around.
We came up with this function to do it quickly. Hope this helps everyone.
CODE
function swap_colorize(obj,properties)
{
var tthis = obj.parentNode;
obj = {};
obj = new KONtx.element.Image(properties).appendTo(tthis);
}
//Usage
swap_colorize( this.controls.myimage, { src:'http.//...image.png', styles: {colorize:'#FF0000'....} } );