A few things to consider when using FTK Imager.

In March 2008 NIST has released their test results for FTK Imager 2.5.3.14. Several problems have been detected:

• with acquisition of a logical NTFS partition;
• hidden by a host protected area (HPA) sectors;
• the sectors hidden by device configuration overlay (DCO); and
• FTK imager didn’t reported the location of corrupted data.

AccessData has released FTK Imager version 2.5.4
Release Date: April 8, 2008

Version 2.5.4 release notes for this version has no mention of any bug fixes detected by NIST.