Are Tivo drives different?

[mike]

I pulled a WD400EB 40GB hard disk from a tivo.
Deleted the partitions with partmgr.
Partitioned and formatted the drive during
the XPSP3 install. C~10GB d~30GB

Windows runs great. But when I try to back up the
drive using Acronis True Image 10, it hangs on
"checking drive D".

Chkdsk d: runs fine, but Chkdsk d: /F hangs
at "the type of the file system is NTFS".
After about 2 minutes it says the drive is in use
and asks to dismount it. I type "Y" and it hangs there
for almost 5 minutes before announcing that the handles are invalid...

Task manager says that the system is 99% idle.
The hard drive activity light is mostly off.

After a total of 10 minutes or so, the 3 phases of verification
proceed at normal speed.

Then the process hangs again after listing the statistics.
Two minutes later, the command prompt appears.

I perform the identical procedures on other drives from
40GB to 120GB and everything works fine.

I have two of the 40GB Western Digital WD400EB drives
pulled from Tivos. They both have the LONG delays in the backup and
chkdsk /F.

Are the Tivo drives somehow different? Can it be fixed?

Thanks, mike