LineTo really CPU-intensive in fractal

When flash has drawn a lot of lines on the screen, it starts to slow down. I noticed this a long time ago, but didn’t really care. But now I’m making a fractal (made out a couple of for-loops to draw lines and some complicated formula) and it’s kinda CPU-intensive: http://www.lbr-designs.be/fractalkirup.html

This is a great way to test the speed of your pc (when flash askes to abort the script, you can say ‘no’)

My question: is there a way to convert all the lines drawn by lineTo (and in my example there are a lot) to an image or something similar or anything that could avoid the slowdown.

Oh and to prove that is slows down when there are a bunch of lines: http://www.lbr-designs.be/fractal2.html (You don’t have to wait until it is drawn to go to the next step (“volgende stap”)). Here you notice around step 17 is starts of good, but after a while it almost doesn’t move anymore (if you can’t see it, zoom in)

Thanks