I am having trouble with this model dvd burner after 1 year of purchase. Dvd writing with Roxio on Sony media takes place with ease but im having problems reading with dis. It doesnot read dvds easily and when it reads them, it just reads the first session that i had written(with Nero...nowadayz i write on d whole dvd in a single session with Roxio)...also it makes krrr...krrr sound repeatedly when it tries and is unable to read the dvd consequently. Cd's on the other hand are read with ease. What's the problem? Plz advise...is it a lens issue or some type of dvd tray issue??