Problem with a scroll bar example from Kirupa

Hi there!
I am using an example from kirupa to create my scroll bar and everything related to it…
BUT, i am having a little bug… since my content is way longer than what the example offers it just doesnt work.

here is the www example from kirupa
http://www.kirupa.com/developer/flash8/scrollbar.htm

While the example used in Kirupa has a main content high(y) of 990 the one that i am using has y=10200.
So when i am scrolling up and down, the down and the up doesnt work as expected.
Why is this happening?
Anyone???
PLS help!!!
Thanks.
Leo.