When setting text through dynamic text fields and string
localization, when line breaking occurs a big gap with white space
is inserted (is not leading as if wrapping occours that white space
is not there).
To reproduce just open the string panel: Window>Other
Drag a dynamic text field to the stage
In the string panel click settings, pick english and leave
replace automatically at runtime
select the textfield on the stage, insert an Id and some text
(with a line break) on the string panel.
run the movie and see the white space beeing inserted!