Problem with setting font in a LiveEffect

I'm adding text objects within a LiveEffect plugin.

Firstly, the text objects that are created has the illustrator default font (Myriad-Pro regular), and not the font currently set in the Character style panel (which is the font I get If I create a new text object myself).

Getting the font from the character style dialog is straight forward.

 ATE::CharFeaturesRef cfRef;
 sCurrentTextFeature->GetCurrentCharFeature( &cfRef);
 ATE::ICharFeatures charFeatures( cfRef); 
 bool isAssigned;
 ATE::IFont theFont = charFeatures.GetFont( &isAssigned);

Then setting the font within a LifeEffect results in a EXC_BAD_ACCESS error:

 TextFrameRef ateTextRef;
 AIX( sAITextFrame->GetATETextFrame( textArt, &ateTextRef));
 ATE::ITextFrame ateText( ateTextRef);
 ATE::ITextRange ateRange = ateText.GetTextRange();
 ICharFeatures charFeatures;
 charFeatures.SetFont( theFont);
 ateRange.SetLocalCharFeatures( charFeatures);

I've encountered a number of things that is "illegal" in a live effect, but is legal in a filter.  Is this one of them?

Setting the font size works however...