Was it a second tab with the option to overwrite or specify a different location?  Or was it the hidden button with "Advanced" on it?
 
  As my old headmaster used to say "Every day a day at school". 
 Quote:
   | I have the tape from the server in another server for recovery (off-line) but NTBACKUP prompts to overwrite the live data, not restore to the off-line server | 
 
   doesn't sound like you do things by half does it?