Sony dvd rw dw d26a problems

hello, I own a sony dvd rw dw d26a usb burner, the burner works fine for most of the time, but say every 6 burns it will coaster about 3 times or so, i am using windows xp sp2, also sometimes in windows explorer the drive name will chage from dvd rw drive to just a regular cd drive, also, when burning with nero 6 ultra, the user read buffer will go up and down and the buffer will go up and down but it will burn successfully, but when it doesnt do that it usually coasters, anyone know what i can do to fix this problem so it works fine everytime and i dont have to worry about it? :slight_smile:
thanks guys any help would be appricated