Yeah I am trying it.
I got it to work with Nibitor fine? (version 2.9a)
Tools - read bios - select device - choose the card.
Tools - read bios - read into Nibitor.
Tools - voltage table editor
Change entry 2 to the voltage you want leave the VID alone.
Save it then use magic iso or whatever to add it to the boot disc image, burn to CD.
Use Nvflash to flash as normal.
My card has always artifacted with the core past 585mhz, it will run fine at 600/715 but ATITool shows bad artifacts, 585/715 is fine.
I started off with 1.3v then 1.33v, 1.35 and finally 1.4
Using detect optimal frequencies the only gains I could see was 5mhz on the memory and 2mhz on the core.
Using Nibitor to read the bios again after flashing shows the voltage as what I set it at but I am not convinced it is actually raising the voltage on the card, possibly a motherboard restriction?
I have tried Rivatuner but can't get it to read the actual voltage correctly, although it does tell me I am running at VID #7 which is set to the higher voltage.
Add me to MSN if you want to try one of the bios' I have modified.