My current bios revision on my card is 1.00.01 SD I believe, and I notice there are two, seemingly newer revisions with the 2.15. prefix.

I downloaded them from this website -
http://welcome.to/3dfxBios

The problem is, when I use the 3Dfx flasher utility program, found in the "utilities" section of this website, on one of the newer 2.15 versions of the BIOS, I get an "uknown manufacturer" error, or something like that.  The 3Dfx program apparently not regonizing the EEPROM or the bios ROM won't let the BIOS flash go forward.

I'm having much difficulty getting my Voodoo3 3000 AGP card to behave properly, as you may read in my "Nightmares" post, so I'm trying anything I can to see if it can help, is why I'm trying to do this.

Anybody know how I can make the flasher utility flash with the updated BIOS rom's?  Or another utility that will do it?

really sounds like your card is broken..anyway, already read the F.A.Q. on http://welcome.to/3dfxBios ? if not, do so, it's really necessary to follow these instructions!..oh ya, as patience noticed: please install at least directx 8.0 or higher for proper driver function.