ActionScript 3.0 :: Text Disappear On Font Size Change And Reappear On Clicking Start Button?

I'll try to be brief. I've built a teleprompter projector file app in Flash CS4 and it works great on PCs & MACs. Only one bug. the program works in three phases: Welcome & instruction screen / Text input screen / Prompter screen.Problem occurs when you first enter prompt screen

basic navigation and functionality includes:

BUTTONS: button to return to INPUT screen, a BEGIN button, a MIRROR text button, and a SAVE prompting position KEYBOARD: SPACE begin prompting, LEFT & RIGHT ARROW increase & decrease font size, UP & DOWN ARROW increase & decrease scrolling speed, HOME returns script to top, PAGE UP & PAGE DOWN moves script by 600 pixels.

MOUSE: MOUSE_WHEEL increases and decreases scrolling speed *(would like to add a ctrlKey modifier to change font size on mouse wheel - another day perhaps)

THE PROBLEM: When you enter the prompt screen and hit PAGE DOWN the script correctly moves down 600 pixels, but does not redraw on the stage. If you then hit PAGE UP it correctly moves up and the text is back on the stage. Hit PAGE DOWN again and it moves but does not render. You can repeat this continuously. I have a Y position reference that shows the Y coordinates of the text field, so I'm confident that the MC is correctly moving, it's just not rendering. If you hit PAGE DOWN and hit BEGIN the text renders in the correct place. Once you start the prompter, you can stop it and use PAGE DOWN and it renders correctly, but if you change the font size larger > 100 and hit PAGE DOWN the font again does not render. Again if you hit BEGIN the font renders correctly in the correct position.

WHAT I THINK: I've been trying to find a way to update or refresh the text field that is being manipulated on PAGE DOWN and font increase; no luck with updateAfterEvent or redraw. I've tried to start and stop the prompter programmatically in one frame at the end of the PAGE DOWN function & font increase.

POSSIBILITIES OR NEW STRATEGY? I'm a media production specialist with a school district in Florida, and I'm hoping to release this app to all our schools and to sourceforge.net. It's a small bug, but I'd rather not have to explain it if I can find a way to fix it. The following code block only contains the functions related to the navigation and prompter text box manipulation.

//Begin button toggle code.Toggle between begin and stop.startBtn.addEventListener(MouseEvent.MOUSE_OVER, startOver);function startOver(e:MouseEvent)[code].....

A Visual Basic & ASP.NET programmer I work with looked at the bug with me, and he believes the error is somehow related to the actual CLICK of the BEGIN button. As I noted earlier, we tried a workaround by using code to start and stop the prompter in one frame after the font size change, but that did not correct the issue. Yet when you physically click begin with the mouse it renders the text.What is it about clicking the mouse that causes the text box to render? Is it a focus issue? Like the keyboard has focus, but when you click BEGIN it returns focus to the text box and it redraws then?