yeah, i got a similar problem, i am a ex-PC user and after switching over to a macbook i got myself an harddrive bay thing that lets me connect my SATA HDD with a usb/firewire rather than a IDE connection.
since the drive was used on a PC, it is in formatted in NTFS and at first i thought it was to do with leopard not being able to read/write ntfs, so i downloaded ntfs-3g and macfuse hoping to get a result but no joy.
the problem wasn't because i couldn't mount it, i think the OS just has troubles reading the drive, i know the bay is working ok, but i have no idea as to why the FS cannot be mounted.
when i boot up, leopard just says "the disk you inserted was not readable by this computer" "initialize..." "ignore" "eject"
ignore and eject don't help and initialize just takes me to the disk tool, but every option is greyed out. I thought it meant my drive was currupted but it isn't because i used disk warrior and it said it wasn't supported and it didn't do i damn thing (i have sent an email requesting a refund, grrrr)
it said the file system is unsupported.
i will post several screenshots, any help will be very appreciated.