For future readers - this problem was most likely caused by the image being deployed to a HDD that was too small to hold the image. This is a common error with non-resizable type images and is normally resolved by using resizable type images or by deploying to HDDs that are large enough to receive the image. Further documentation can be found in the WiKi here:
https://wiki.fogproject.org/wiki/index.php/Troubleshoot_Downloading_-_Unicast