problema lg GSA-5160D con memorex dvd+r 16x

Antes usaba verbatin dvd+r 8x sin problema, pero compre unos memorex dvd+r 16x y no me deja grabarlos a mas de 4x y encima despues de grabarlos no puedo leerlos. Sabeis a que puede ser debido? he mirado en la web de LG y no encuentro ningun actualización de firmware.

En la bobina pone esto:
"ATTENTION DVD Drive Owners.<Updating your drives and recorders for 16x DVD+R dics. The firmware upgrade requires downloading software from the internet onto the computer for computer drives or onto a cd/dvd for a home dvd+r recorder. Many manufacturers of home dvd+r recorders will provide users with a cd that contains the software ans instructions on updating the firmware in the recorder. The firmware upgrade will allow recording onto 16x dvd+r disc but will not increase the speed of the drive. Fir more information about this issue, please visit www.memorex.com/service_support/faq.php"

Gracias y perdon por el tocho.

Un saludo