Have you updated your backup software since your backup file was created? I've seen new versions of backup software fail to recognize files created by older versions, so that might explain why your recovery media doesn't see the external drive as containing a backup file. But if the external drive is formatted in NTFS, I can't see any other reason why your backup software would have a problem with it, unless the backup software isn't working correctly. I'm assuming you've verified that a backup file is actually created by the program?
I'm not familiar with the backup software you're running, and it couldn't hurt to contact their support. Just like Platypus, I've run Acronis for years on my own stuff and most of my client's computers.
Platypus, it's good to see you haven't fallen off the planet.
Edited by slgrieb, 03 July 2013 - 03:44 AM.