I am unable to run either QT movies or games requiring OpenGL on my PPC6500/300 without getting distorted sound, static or jerky motion. If I revert to an older version of ATI software and older version of OpenGL, I do not get the sound distortion but, of course, cannot run some games that require the latest version of OpenGL. I have found comments on other forums regarding the PPC 6400s & 6500s having similar problems. I do have a Sonnet Crescendo 400 L2 G3 card installed. I have disabled that but there is no difference in results.