Does this work? I've set TNA_Image to both a label.image and a bitmap.image object on a clicktab node, and it just ignores it and shows TNA_Text (if specified) or nothing. I've tried the same thing on both OS4.1FE update 3 and OS3.2.3, and it doesn't appear to work on either.
I'm guessing this has never been implemented and nobody has noticed? Or I'm doing something wrong (not sure what I can mess up here, so if there is a working example I'd like to see it).