PC3000 SAS always shows 1 sector less than normal

[ThomasH]

I've only used the PC3000 SAS for a few cases so far, but I notice that it always shows drives as having 1 sector less than they should in Data Extractor. PC3000SAS utilities detect the normal sector count, it's in DE that the sector count lowers. It's the same with both SAS and SATA drives.

This is NOT a matter of showing 1 sector less as the "last sector" since the starting counts at 0, as is normal with all other tools and software I know, PC3kUDMA included, on the same drives.

For instance, I'm working with some 300GB SAS drives.
Winhex shows the total sector count as 585,937,500.
DE / PC3k show the total sector count as 585,937,499 (and shows the last sector on the drive as 585,937,498).
When DE cloning finishes, it states that 585,937,499 sectors have been cloned successfully, and 0 sectors were bad, but the last sector does not clone.

Is there a reason for this?