so.. i am on os x but willing to create a knoppix usb drive if necessary. i need some help with testdisk which i have been using with os x- the testdisk forums are slow and i'm not sure if i will get another response. i have a western digital 2tb my passport, formatted fat32, which now has physical damage from use with a friend's netbook. i cloned the drive to a new 2tb drive with ddrescue but it could not save 4096 bytes of data, which i think was at the beginning of the drive. here is my testdisk log from the cloned disk. the hfs+ partition that it sees is not the one i want, that was the formatting on the drive i wrote to. i need to work with the fat32 partition it says it cannot save.

Analyse Disk /dev/rdisk2 - 2000 GB / 1862 GiB - 3906963456 sectors
Geometry from i386 MBR: head=255 sector=63
BAD_RS LBA=1 1339
check_part_i386 1 type EE: no test
get_geometry_from_list_part_aux head=1 nbr=2
get_geometry_from_list_part_aux head=8 nbr=1
get_geometry_from_list_part_aux head=16 nbr=1
get_geometry_from_list_part_aux head=32 nbr=1
get_geometry_from_list_part_aux head=64 nbr=1
get_geometry_from_list_part_aux head=128 nbr=1
get_geometry_from_list_part_aux head=240 nbr=1
get_geometry_from_list_part_aux head=255 nbr=1
Current partition structure:
1 P EFI GPT 1 3906963448 3906963448


Warning: Bad starting sector (CHS and LBA don't match)
No partition is bootable


search_part()
Disk /dev/rdisk2 - 2000 GB / 1862 GiB - 3906963456 sectors
FAT32 at 8/0/1
FAT1 : 32-476839
FAT2 : 476840-953647
start_rootdir : 953648 root cluster : 2
Data : 953648-3906963439
sectors : 3906963454
cluster_size : 64
no_of_cluster : 61031403 (2 - 61031404)
fat_length 476808 calculated 476808
FAT differs, FAT sectors=0-16/476808
heads/cylinder 255 (FAT) != 1 (HD)
sect/track 32 (FAT) != 1 (HD)
set_FAT_info: name from BS used


FAT32 at 8/0/1
FAT32 LBA 8 3906963461 3906963454 [UNTITLED]
FAT32, blocksize=32768, 2000 GB / 1862 GiB
This partition ends after the disk limits. (start=8, size=3906963454, end=3906963461, disk end=3906963456)


HFS+ magic value at 409640/0/1
part_size 3906291632
HFS 409640 3906701271 3906291632
HFS+ blocksize=4096, 2000 GB / 1862 GiB
Disk /dev/rdisk2 - 2000 GB / 1862 GiB - 3906963456 sectors
Check the harddisk size: HD jumpers settings, BIOS detection...
The harddisk (2000 GB / 1862 GiB) seems too small! (< 2000 GB / 1862 GiB)
The following partition can't be recovered:
FAT32 LBA 8 3906963461 3906963454 [UNTITLED]
FAT32, blocksize=32768, 2000 GB / 1862 GiB
get_geometry_from_list_part_aux head=1 nbr=2
get_geometry_from_list_part_aux head=8 nbr=2
Warning: the current number of heads per cylinder is 1 but the correct value may be 8.


Results
* HFS 409640 3906701271 3906291632
HFS+ blocksize=4096, 2000 GB / 1862 GiB


interface_write()
1 * HFS 409640 3906701271 3906291632
simulate write!


write_mbr_i386: starting...
write_all_log_i386: starting...
No extended partition


TestDisk exited normally.

thanks much.