The problem it seems, by having firefox look at the HTML code, is when closing "segments" (sorry, I don't know the proper terminology yet) of code Tersus puts a "/>" at the end. Firefox doesn't seem to like the "/" part.
BTW, I'm using FF 4.
That said, so far this is looking like a great product. Just been going through the tutorial, and this seems to be the website creation program that I've been looking for. While I can code, I'd much rather not.
For best results, use the Firefox browser..