I sent you the reply. The discussion will continue by email until the problem is found.
During our evaluation of the software we had the same issue - scheduled backups (using Windows Task Scheduler) were not working (Server 2008 R2). In our case it was because we run the task under a specific domain user account which did not have a profile on the server. We logged into the server under the specific user account and the scheduled backup started working. We believe this is because when the backup job runs, it appears to build the backup zip file under the user's profile. No profile = no way to build the backup file. HTH.