Knoppix crash during file copy

History: I got a HDD that does not boot, after install fresh XP in a new HDD, this supposely defective HDD fail to be detacted (says need format).

Good news is that I recovered a lot of stuff via Testdisk (90%) but trying to use KNOPPIX to get back those cannot recover so far.

Problem: Under testdisk, some recovered files listed with ZERO KB..(this is th 10% of file i fail to get back)

Assume the HDD got file A, B, C, D, E only ... and file C is the one that has zero(0) KB when recovered under testdisk

Then under KNOPPIX, the copy process is OK and all smooth with file A, B but then when it reaches to file C, it STALLS and frozen up everything.

QUESTION: What can this mean? is it that my HDD has physical sector damage that is already permanant? and there's nothing I can do even with KNOPPIX?