I have tried about 6 diff HD diff size and diff format (NTFS, FAT32 etc). Everyone of them were formatted and updated on WinXP. Double checked with WinXP and no problem. Also checked with a real Macbook pro running 10.6.6 and no problem at all. I had iATKOS s3 v2 installed and it is on 10.6.3 Can't find any problem except for this. Some of these drives won't mount on the iATKOS. I can see all of them in Disk Utility but when I try to right click and mount it it will fail. Tried doing mounting in terminal it also failed. I can't move things off the drive (some drives are 1~2TB) and do a new partition. Did a disk check (run a long time... ) it says found something on some drives. But some of these drives I used for a long time and never had problem in XP. Is there any reason to it? So I can still sure that all the drives will work on XP and real macbook pro not sure why in iATKOS s3 installation it just won't mount.