Ken,
With the lack of matching meta data, are you saying that if I accidentally attempt to restore one of these files I might crash, or would it just not be able to do the restore. I don't really need the old backups, so not being able to use them would not be an issue.
Am I right that simply deleting them from the filedir would be a bad idea. A really, really, bad idea?
By the way, now that I have succeeded in clearing enough space on the server so that it has allowed me to make a recent backup of each of my two courses, I am considering wiping everything from the server and doing a fresh install.
If I were to do this, and simply allow it to name the moodle data folder the default "moodledata" and leave everything in autobackup settings at default, do you think I could avoid the problem of zombie backup files in the future. I am still not clear on why moodle cannot find and delete backup files that have been deleted from within moodle.