A folder must be snap shot enabled before a snap shot can be taken of the files within the folder.  This is done as follows:

• Click on Tools \ Options
  
  

Ensure you are in the Drives tab in the bottom half of the screen.

    

• Tick the Snapshot checkbox for any folder that you wish to be snapshot enabled.
  
  
• Click Update drive mappings.
  
  

The folder will then be snapshot enabled.

Permissions to use snap shots per folder must then be set for each user.  Setting snap shot permissions per user.