My experience (ten years ago) with computer-generated faxes was that the fax box used to send the fax was a critical factor. I had to limit my code to the sub-set of the language that the box understood. I was hand-coding HP PCL but I suspect that the principle is the same.
However, I wonder why you are generating faxes today??? Who still has fax machines, and would they welcome receiving your faxes? And why are you viewing the HTML in Front Page??? It's not exactly the most reliable interpreter/writer of HTML. I suspect that you might be better off generating the documents in your favourite word processor, and outputting them to PDF instead of HTML.