Something's recently changed, where when one replies to an existing post, the fonts no longer stay "neutral". Then, to make matters a bit worse, folks (like myself) who notice something going on each try to correct it, but we're all trying slightly different approaches, and the resulting threads show several different appearances, rather than the intended standard one. (Part of the correction issue is that these text boxes start with a neutral (unspecified) font and size, but there doesn't seem to be a way to select text and then apply those attributes.)
Sorry that the above isn't very clear; it's 1 am here, and I need to get some sleep. Maybe someone with a more clear head can help clarify.