We're still getting too many coasters. We render to mpeg2 in MS, author in Ulead VideoFactory. DVD's will freeze part way though playback, or will temporarily stall than continue playing. We have tried different media, different computers, and different burners, current burners being Plextor PX-708a and Sony DRU-510A with most current firmware. We have about a 50% error rate. Could it be Ulead? Any ideas anyone?