Fullscreen performance

Hi,

I’ve created a SWF that changes it’s width and height to match the browser’s size.

the performance difference is huge when i view the site in a small window(800600) or a maximized window (on a 16801050 display) . I don’t know what could affect performance that much. the content is viewable either way. the only thing that changes is the amount of “background” that Flash has to draw… i guess. is there a way to tell Flash to re-draw only one part of the screen on each frame? or am i viewing this issue from the wrong angle?
any input would be appreciated.