Partition Recovery - A Real Poser

Greetings,

Here's a challenge for you all . . . . A client came in with a Western Digital 250 GB USB external SATA hard drive that Windows XP would not recognize any more. After some questioning she admitted to trying "some software" to try and get the drive recognized on both a desktop computer and a laptop, both running XP. This same hard drive was plugged into a Mac laptop but mounted just fine in XP afterwards, or so we have been told.

TestDisk did not find any partitions when it looked for Intel or Mac partitions running both quick scans and deeper scans.

Running TestDisk to look for "non partitioned space" revealed 3 HFSX partitions that can't be recovered.

TestDisk also gave the following message when starting the tests:

"The harddisk (250 GB / 232 GiB) seems too small! (< 12202034 TB / 11097685 TiB)
Check the harddisk size: HD jumpers settings, BIOS detection. . ."​

I have always used TestDisk to recover damaged partitions. Is there a better or different tool that we might use with OS X that would be effective in recovering these partitions?

Any helpful suggestions are much appreciated, it will be a serious bummer to have to tell the client that her files are gone forever and we want to exhaust all of the possibilities before doing that.