I received two external LaCie d2 Quadra HD (500GB and 2TB) recognized as NTFS on Windows XP and Windows 7. The same disks attached on a Mac with OS X 10.6.4 and NTFS for OS X 8 brings up a popup window "The disk you inserted was not readable by this computer". I disabled NTFS for OS X 8 -> same thing. I tried on another Mac with OS X 10.5.8 with the Paragon driver -> same thing. I tried with Tuxera NTFS -> same thing. I checked the disks on Windows with Disk Management and I can't see anything wrong. What else can I do? Is that a known issue?