Chinmonster has posted a beta bios for the 3D Prophet II video card:
First of all, special thanks to Simon and Adam for sending me these files. This BIOS was supposedly emailed to some 64mb Prophet II owners per special request to Guillemot´s UK tech support. It is unofficial and obviously, not supported by the company. Hopefully for some of you who are having problems with your cards, this BIOS will solve some of them.Download
Speaking for myself, I am currently using it and it´s been pretty stable so far. The most apparent change is the core setting which as been lowered to a nominal 200mhz core. The default setting for the memory is still at 365mhz. As far as I know, this BIOS is intended for 64mb Prophet II owners ONLY. Do not use if you have something else!
Flashing your card with this BIOS WILL void your warrantee so I recommend that you only use the following procedure to load the BIOS into your memory instead. Should you have problems, you can simply remove the lines from your autoexec.bat and config.sys files and you´ll be back where you originally started using the original factory BIOS with warrantee intact.