Sounds like your Voodoo Monitor driver in devs:Monitor is not
getting loaded for some reason or you have a typo in the BOARDTYPE = line in the "Voodoo" Monitor driver tool types.
If you boardtype= tool type is not the same as the file it is attached to it will not work. As lest that was the reason I was haveing what sounds like the same problem as you have the first time I tried to setup my Voodoo3 card with my MediatorSX PCI busboard.
I don't know if it makes any difference but I have my network card in the top slot my sound card in the one bellow and my Voodoo card down the bottom of the case in the second last slot. I would have put it in the bottom slot as I am told that is what amiga kit recommends but as I have my A1200 in a mk4 eyetech tower I cant use the very bottom slot.