Just remove all other extensions and try the card on it´s own, worked for me and my GVP GForce Combo 040 at 40 Mhz.
I only had a 2 MB Ram Card in my 2000er but that gurus the complete systems, after I removed that one, the GVP card worked fine, after installation I also put back the RAM card and it works until today
Oh btw. the GVP GForce Combo also got a SCSI-II Controller onboard, nice card IMHO
