Using htmlText in TextFields

I’m loading content from a text file into a text field in Flash. In that text file I have some simple html tags like <b>, <i>, and <img>.

I’m setting the textfield as html text:
myTextField.htmlText = myContent

The img tags work fine, but for some reason the bold and italics are not displaying…the tags are being correctly stripped from the text, but there is no bold or italic text. I’m embedding all the characters I need, but do I need to somehow embed the bold/italics versions of those characters?

Thanks.