Flash CS3 Pro and Dynamic Text strange problem


I used Flash MX/actionscript before to change the text of a simple text box that was converted to dynamic.

For example on a simple button I used an action like this

on (release)
mytext.text = “Simple message”;

and immediatelly I saw the new message inside the text box.

Now with CS3 I have a problem with that. The text I write inside the textbox is not shown and when I click on the button I see also nothing. If I try to select the text (selectable option enabled) then it appears to the right side of the text box.

What’s wrong here ?

See my attachment.