Motion Sickness In 3D Games?

James Ensor asks: "I've always been subject to pretty bad motion sickness ever since I was a kid. I especially have problems with some, but not all 3d games. Has anyone else had this problem and/or have any insight into why some games are worse than others/how to make games that don't cause it? An interesting side note, Games based on DirectX have been a much bigger problem for me than anything based on OpenGL. In fact, in games that support both, I often get sick playing the DirectX version, flip over to openGL and have no problems. Any thoughts?" I can see how some games might cause some motion sickness, but the DirectX/OpenGL connection is a new (but highly quesitonable) addition. Is anyone else afflicted with a similar malady?