Ok, that clarifies it. Anyway, it really doesn't matter whether the virtual disk is sparse or full provisioned, the guest - in your case the image restore application - will see the same disk size. Which imaging application do you use, and does it show the disks which it detects? Maybe it's an issue with the virtual disk controller and that the application doesn't recognize the disk at all due to e.g. driver issues?
How did you configure the VM (guest OS selection)?
André