Improving the rendering performance

I am working on a large project and I would like some advices about improving the rendering performance when scrolling some content.

I have a large sprite with a lot of content that I need to scroll and the problem that I am encountering is that when scrolling this big sprite, the rendering of the Flash Player seems to slow down and the movement is choppy.

I wrote a custom scrollbar class that simply updates the target sprite y or x properties on an enter frame event.

The large sprite that I am scrolling mainly contains other sprites that have drawn shapes, loaded bitmaps and text fields.

Considering that I am simply moving the sprite, there are no other animations happening, nor other intensive processes at the same time, I do not think that it should be that resource intensive as to slow down the Flash Player that much.

What can I do to improve the performance when scrolling the sprite ?

(Just to give a rough approximation, the sprite that I am scrolling contains around 20-30 sprites with drawn shapes, 2-5 loaded bitmaps, 5-10 text fields.)