hope sombody can help my with this

i'm trying to animate a font in vertical lines of single characters replacing the previeous one by one down and so on... done it with single frame animation...

but after saving my file i keep loosing some of the letters like w, k,.... in the whole animation....
if i click on the text they show in the text field but as soon as the field is gone or when i test the movie they are missing!
i've although noticed that the enclosed spaces in the letters appear to be filled....
the font i'm using i found in flash mx.. it's called: vt100