IE:hover problem solution
For some reason when you hover over a transparent background in IE, it considers the mouse to not be in the dom object (or in this case, the span) anymore, but instead in the element below it and calls the mouse out event.
For some reason when you hover over a transparent background in IE, it considers the mouse to not be in the dom object (or in this case, the span) anymore, but instead in the element below it and calls the mouse out event.