ActionScript 3.0 :: Inconsistent Behavior With <b> And <i> In TextField?

I've created a text field, styled it with CSS imported through an XML fragment, etc., and almost everything works as it should.

The exception (of course!) is with <b> and <i> tags. I've included the relevant font outlines in my SWF, and the bold or italicized text does in fact show up, but here's the thing: sometimes, the space between a word and the opening <b> or <i> tag disappears!

My text is all read in through XML <![CDATA[]]> blocks. If I had the following fragment:

Code:
<![CDATA[This is <b>bold</b> text. And this is <i>italic</i>.]]>

The output might looks like this:

This isbold text. And this isitalic.Or it might looks like this:

This is bold text. And this is italic.

The problem is that the behavior changes according to the alignment of planets and phases of the moon or something I don't know. I tried forcing an extra space between opening tags, which would correct it in the instances where the space is deleted, but it adds an extra space where it's not!