Letter Spacing question

Does Letter Spacing accepts decimal value?
I applied a 0.1 letter spacing to some static texts.
The texts does show a little extra spacing in stage
However when I Test Movie it, the spacing seems to turns back to 0.

Just take a look at the attached pictures.
The text with 0.1 spacing and the red rectangle have the same length in stage area,
but when I play the movie, the length of the text is shorten than the same red rectangle.
Any clue? :q: