Front Page is considered a course, but I've only seen front page backups when autobackup is setup and functioning or manually backing up the front page.
Site is called 'Moodle 25' short name 'MDL25'. In the running of cron:
Running required automated backups...
... started 16:07:53. Current memory use 89.4MB.
Backing up Moodle25...
complete - next execution: Tue, 03 Sep 2013 02:55:00 -0500
In the cron job it should show all courses and if a course has not been changed (if backups left at their defaults) it should inform:
Backup of 'iPads 101' is scheduled on Tue, 03 Sep 2013 02:55:00 -0500
Skipping iPads 101 (Not modified in the past 5 days)
At the end of that routine:
Sending email to admin
Automated backups complete.
Do you get a message like this?
Date: Sun, 1 Sep 2013 16:07:58 -0500
From: Admin User <ktask@site>
To: Admin User <ktask@site>
Subject: MDL25: Automated backup status
Summary
==================================================
Courses: 22
OK: 1
Skipped: 21
Error: 0
Unfinished: 0
Warning: 0
Backup completed successfully
What are your autobackup settings?
Could you possibly send a screen shot/edited text of what you see when cron is run?
'spirit of sharing', Ken