Hi,
Alarm bells are ringing for me when you say "We use model-specific sysprep files that copy SATA drivers in the SysprepMassStorage section". Are you ammending the SysprepMassStorage section at image deployment time and injecting files into the image? If you are, this does
not work unless you are using technology in addition to sysprep (like DeployAnywhere) which makes deployment time
file and registry injections.
If you don't use the really clever stuff you need to sysprep your images with all the mass-storage drivers you are likely to see in the next few months as well as those we already have in you environment. This will allow all your models to see the harddisk when they boot.
There are lots of articles and discussions on Connect on Sysprep and HII. He's a couple it would be worth a look over (if you haven't already),
Kind Regards,
Ian./