Scrollbar seems to have limited length. help?

hello, this is my first post. After many weeks of searching I’m still stuck…

Issue is, I have a scrolling dynamic text field (reading a .txt file) made with the Flash MX Scrollbar component and it seems to have a limit to it’s length? Is this a true assesment? I would like it to continue past this limitation…

here are my settings:
Dynamic Text
various font settings, Arial, Bold, 15 points

Please help. Thanks