You need to get the oven hot enough, long enough, so the masonry is not wicking heat our during your baking. This causes the temps to decrease pretty rapidly.
See the discussion on this thread:
http://www.fornobravo.com/forum/f11/...bake-1208.html (Dissapointing Bake)
As to why you have to rake out coals, I am not sure you have to, but it makes your bread cleaner to sweep the hearth clean...
Drake
Drake