Until your problem is resolved, you might experment and see if the -a option and its prompts also works. if that works, you may find you prefer responding with defaults (pressing ENTER twice) easier than typing "quit". And for either amd64 or i386, the
boot.conf(5) file can be used to set a boot command with either -c or -a, so you need not type one or the other at the boot> prompt.