TLFTextField vertical scroll - scrollV not working?

Hi. I'm using Flash CS6 on Mac OSX 10.7 and I was trying to use a TLFTextField and do some animations depending on its vertical scroll. I have an example here:

http://ecstweb.comuv.com/temp/forum/anim2.html

The text field intance is named txt01 and the text field that shows the value of txt01's scrollV property is named txt_scroll.

My code is:

Code:

---

import flash.events.*;
import fl.text.TLFTextField;

txt01.addEventListener(Event.SCROLL, itScrolled);

function itScrolled (e:Event) {
    var s:int = e.target.scrollV;
    txt_scroll.text = String(s);
}

---

When I scroll down, scrollV is always 0. If I reach the bottom of the text, when I scroll up scrollV is displayed correctly, although when it's on empty lines it displays 0 again, which makes no sense to me. What am I doing wrong? How can I get the correct scrollV value?

Thanks.