Try creating the OS3.9 emergency disk (from the os3.9 install menu), booting from the emergency disk rather than from your hd0 to do the install of os3.9.
PS don't forget - mapped rom on the 1230iv is when the pins on the blizzard board are NOT jumpered. Confused the hell out of myself with that one the other week and had to refer to the 1230iv user manual to refresh my memory (no pun intended).
As Thomas said though, if you don't own the kickstart rom hardware you shouldn't be using the softkicked ones. They're pretty cheap on ebay at the moment anyhoo.