This is how I do it in AS3/CS5
Just a note, you also need to create a new Font in the library for embedding to work.
Actionscript Code:
var a2iText:TextField = new TextField();
var a2iTextFormat:TextFormat = new TextFormat();
a2iText.embedFonts = true;
a2iTextFormat.font = "Verdana";
a2iTextFormat.size = 30;
a2iTextFormat.bold = true;
a2iTextFormat.italic = false;
a2iTextFormat.color = 0xFF0000;
a2iTextFormat.align = "center";
a2iText.defaultTextFormat = a2iTextFormat;
a2iText.type = TextFieldType.DYNAMIC;
a2iText.selectable = false;
a2iText.autoSize = TextFieldAutoSize.CENTER;
a2iText.x = 50;
a2iText.y = 50;
a2iText.antiAliasType = AntiAliasType.ADVANCED;
a2iText.sharpness = -200;
a2iText.text = "My Text";
addChild(a2iText);