Since so many DRU500 owners having disc reading problem after certain period of use time https://www.videohelp.com/forum/viewtopic.php?t=197621 I wonder has Sony improved that on their later models? Any HEAVY users with later models experiencing similar problems? If I have to buy another burner shall I stay away from SONY? http://reviews-zdnet.com.com/4505-3205_16-30581840.html?tag=srch