Justcloud will backup your computer everyday if your computer is turned on and connected to the internet. If your event log is showing that a file has not been backed up for a while it is probably because the file has not been changed since it was last backed up.
You can check on your backup history by visiting this page: https://my.Justcloud.com/files-and-data/backups
If you feel that your backup is not running correctly please temporarily disable your firewall and resume the backup.