I also have a Diamond Viper V550 in my computer. That makes three of us with really, old video cards. I guess TB gamer's don't need no stinkin' GeForce III, do we?
I've also seen an error message when I perform the actions you described. My workaround is to not do that anymore.
Hopefully, the GeForce II MX will drop to $50=$75 USD when the GeForce III starts showing up in stores, and all three of us can buy better video cards that don't run into these problems.