I created vertical scrollbars/scroll panels in Flash Catalyst 5.
I Published to SWF.
Inserted the scroll panels in my Dreamweaver /web page.
They performed well as expected.
THE problem: when I previewed them in any browser and then enlarge the web page by pressing the command /plus sign all of the page elements enlarged with each size increase — the panel does not. It retained its size leaving a vacant white background area that increases in size as the page increases in size.
Below are the before & after the increase in page size.