Ryzom

I just changed my video card from a Geforce Ti 4400 128mb to a Geforce FX 5900XT. In the character loading screen, my character models are all flashing. When i enter the game, items like crates and tents flash as well. I am using the latest Nvidia drivers and i have also tried alternating between directr3d and opengl with no results

Maybe you should try uninstalling older versions of the nVidia drivers and then reinstalling the lastest certified version. You can find some driver uninstall utilities here:
http://downloads.guru3d.com/download.php?id=5