Acronis 10 and USB HDD

Hi,
I'm running XP Pro and recently bought a new SATA 1 TB HDD c/w a docking station. I have Acronis 10 and am very happy with the program and clone my secondary internal HDD quite often. However when I tried to clone the new SATA drive via a USB, the program said it couldn't find it after it rebooted my computer.
I went through the whole process with Acronis, which recognized the attached USB connected HDD but when the program restarted my computer to lock the C drive it failed to find it again.

Any Ideas,

Dave