Hi,
This will sound strange, but... Try to run this patch before activating the Voodoo monitor driver.
http://aminet.net/package/util/misc/dtackIt does work for my setup with Mediator and Voodoo3 on my A3000. The negative part of this patch, is that it makes Warp3D stuff displaying gfx errors and glitches.
But I only have to run this patch on a cold startup, and often when doing later reboots, I can activate the driver without the patch. I got a check-line in startup-sequence, if I press down "Alt"-key the patch will be executed.
Bye,
Dagfinn