Certain backup applications and services cannot be used when Surfulater is running and has Knowledge Bases open. This is because Surfulater requires exclusive access to its Knowledge Base files and certain backup programs also require exclusive access. When this happens Surfulater can be prevented from saving knowledge base files which can lead to you loosing files or them becoming corrupt.
This is especially true of Dropbox and you must not locate your Knowledge Base files in a folder that is synchronized to Dropbox. You can copy them on a regular basis to the Dropbox folder as part of your backup regime.
The crucial point is to to ensure Surfulater is closed when you back up it's Knowledge Base files. And don't locate your KB files in a folder that is backed up by real-time background applications.