When you run sysprep /generalize /oobe, you are "cleaning" the image of the driver, so it cant load the storage driver (even on the same machine).
You can force sysprep to leave the drivers, but that can get messy and cause other problems with your image.
http://technet.microsoft.com/en-us/library/ee832798(v=ws.10).aspx
Probably the best way is to use your current image and then inject the appropriate storage driver. This is very easy in Provisioning with the HII template action, but if you are using normal OSD You can do the same thing with dism.exe.
After you restore the image, but before you reboot, try this.http://technet.microsoft.com/en-us/library/dd799258(v=ws.10).aspx
specifically "Dism /image:C:\test\offline /Add-Driver /driver:C:\test\drivers /recurse"
-Tracy