Yes, I think Wiggler13 is on the right track.
Unreal recommend using the glide drivers but many graphics cards no longer support it...
http://www.nvidia.com/object/IO_20011120_4349.html
Does my NVIDIA-based graphics card support Glide?
NVIDIA-based graphics cards offer hardware 3D support for the industry’s two standard APIs: OpenGL and Direct 3D. Most games available support one of these two APIs, or both. Some older games support a different API called Glide, which was a proprietary API designed for older 3dfx graphics cards. Since Glide was written specifically for 3dfx graphics cards, games running in Glide mode will not work with NVIDIA-based graphics cards. If you have a game you wish to play in hardware 3D mode, select either Direct 3D or OpenGL for your 3D device from within the games settings.
