Slow drawing

Hello,
I’m creating a website that relies heavily on drawRect to draw boxes dynamically. I’m only drawing 3 boxes at all time. I’m getting terrible performance. I remember reading about using default lineStyle or no lineStyle to speed things up, so i tried it. It made a pretty big difference. Why is lineStyle so slow? is there a way to speedup drawing? I must be doing something wrong. There’s no way that some people can create decent 3d application with AS3 but i can’t even draw 3 2d boxes without killing my CPU…