If you'd like the inbetween values in a tween to always get rounded to the nearest integer, use the roundProps special property. Just pass in a comma-delimited String containing the property names that you'd like rounded. For example, if you're tweening the x, y, and alpha properties of mc and you want to round the x and y values (not alpha) every time the tween is rendered, you'd do:
TweenMax.to(element, 2, {x:300, y:200, alpha:0.5, roundProps:"x,y"});
