greetings, smarter people than me....

I've created a box with scrolling text inside (a letter). However, when scrolling down, it suddenly stops, as if I hadn't made something big enough. I'm just not sure what that "thing" is.

You can see the strange phenomenon (or example of my inexperience) right here:
http://www.ireallyshouldbewriting.co...ut_inwood.html

My .fla file is here: http://www.ireallyshouldbewriting.co...lling_test.fla

My .swf file is here:
http://www.ireallyshouldbewriting.co...lling_test.swf

and the HTML doc is here:
http://www.ireallyshouldbewriting.co...ling_test.html

Of course, I'm working on a deadline because I'm trying to raise money but don't want to send out the URL if the site makes me look like a ninny.

does anyone know what mistake I've made?

THANK YOU, I really appreciate any help.