Nero BackItUp restore issues



I wonder if anyone can help me out.

I am currently backing up “My Documents” to and external hard disc using nero BackItUp.Whenn trying to restore these on another machine, I can double click the individual files and they restorefine, but if I want to restore the whole backup by double clicking the .nbi file, starting the backup produces a dialog box stating that “File xyz is not available in the backup folder”

Can anyone help me around this? I don’t understand how you can’t restaore a file unless the original file is there, surely this defeats the whole point in backing up.

Any help much appreciated.