volgens Ken Task.
Yep! That would cause errors in automated backup also!
http://tracker.moodle.org/browse/CONTRIB-3534
What is the default course format? Topics/Weekly? Are you using an add-on course format?
Any chance of upgrading the site to at least the highest 2.3.x? Your current version 2.2.6 is next to 'slide' into 'Supported for security fixes only'.
BTW, I know this doesn't help you, but I do have a 2.2.6 site using automated backups and it functions just fine. Site is Linux OS, however.
'spirit of sharing', Ken