Snapshot not transferring back to Amazon S3

Hello! I have been running Snapshots pro on multiple websites for over a year and everything I thought was running just fine. However, I'm having trouble with the backups for my web page.

Specifically, Snapshots isn't
1) running automatically (even though it says that it is, there are logs that say it is, but there no backups locally or on S3)

2) transferring backups to S3

I should point out that I'm also running Snapshots on another page I manage and I have double checked that the settings are identical (heck, the 2 sites even use the same S3 account to store the backups - different folders on s3 though).

The only difference between the 2 sites is that is running an older version of Snapshots, but obviously I'm afraid to update given the problems I'm having.