That happened to me before too, you need to install your video card's linux drivers, nVidia ones are really easy, but ATI's can be a pain. I've got dpball running fine on my desktop, but my laptop has an evil little ATI IGP that the ATI drivers don't cover, thus it runs dpball in slow motion, yet Quake 3 will run fine. So lets hope you have nvidia, and go install your drievers.