This is a Heads-Up for everyone that uses the AC Backup Serivce - their servers went down, and were down all weekend.
The Backup Failed messages that you got were your local server not being able to connect to the AC backup servers. For your own peace of mind, I would check your backup directory to make sure the ENC files are there, and of the same or larger size that the previous files a rough means of validating that they ran completely.
Apparently there is no one monitoring operations on the weekend, so they were not aware until they came in today.
Technical Support recommends that you run a manual backup now, so that it uploads.