Doesn't Windows have a habit of nuking the first blocks of disks it doesn't recognise? I know it used to, as it's caused a lot of corrupt hard disks by overwriting its own gunk over perfectly valid but foreign partition tables.
I can't remember if it still does that, or how to get round it, but I know in the original Siamese system which shared a SCSI chain there was something you had to be careful of to stop Windows nuking your Amiga disk.
But that's all from memory. I may be mistaken.
