AS2/CS4: Embedded font, html, dynamic textfield, missing characters

I have content which is dynamically loaded into a textfield:

import TextField.StyleSheet;
var myStyleSheet:StyleSheet = new StyleSheet();
myStyleSheet.setStyle("body", {color:'#0E283D',fontFamily:'DJVRegular',fontSize:'14',textDecoration:'none',textAlign:'justify',leading:'5'});
myStyleSheet.setStyle("a:link", {color:'#330000',fontFamily:'DJVRegular',fontSize:'14',textDecoration:'underline',textAlign:'justify',leading:'5'});
//etc.

var myTextField:TextField;
myTextField.html = true;
myTextField.styleSheet = myStyleSheet;
myTextField.text = "Some text with html tags";
myTextField.embedFonts = true;

Fonts are in my Library, exported for AS in frame 1; text formatting works. What doesn’t work is that certain characters are missing: e.g. the Polish łńśćżź and the entire IPA range. If I delete the line with embedding, text is displayed in some default font, but the characters are there. The problem is that I need to have that particular font in the project, so is there a way to keep the font and display all the characters?

Also, these characters are missing from static fields when I test the movie, which wasn’t the case earlier.

TIA,
Ninna