Has anyone tried to upgrade the 80 gb hdd on their pioneer dvr520, to a 160gb? to give the same capacity as a 720 Any advice, Pitfalls etc. Will the 520 recognise the extra space? I understand that they use an oem, segate drive, would a different brand suit? Could you use a drive greater than 160gb? Any advice would be much appreciated. Even if its general advice, ie. not specific to pioneer units.