So I just got a new phaser 6510/DN printer which supposed to have duplex page printing ability. I'm running windows 10 on my pc but thet wife is still running Vista. I have the V4 drivers loaded she has the V3 drives and the duplex option is greyed out. How do I enable it for Vista?? The V4 drivers aren't listed as an option when you select Vista on the support page for drivers etc.