I had this problem too. I wonder:
add vgabios.bin pci1078,0104.rom 0
^ is that a
letter "O" or a number "0". It looks like a zero.
I think it needs to be an o?
Sorry, I am running on memory here, and can't test it right now, can
you verify that you are using the right "type" as the
final argument?
ron