Maybe it just works better late at night... my overnight scheduled backup ran fine:
17th Jun 2012 3.04.19 AM Information Backup complete.
17th Jun 2012 3.04.18 AM Information Retention was not required, you are still within your maximum quota.
17th Jun 2012 3.04.18 AM Information The online vault has successfully processed the backup data.
17th Jun 2012 3.03.33 AM Information Transmission of the backup data to the online vault has completed.
17th Jun 2012 3.02.50 AM Information Deleted files processing completed.
17th Jun 2012 3.02.50 AM Information File collection completed.
17th Jun 2012 3.01.00 AM Information File system scan completed.
17th Jun 2012 3.00.46 AM Information Folder /public_html/wp-content/plugins/wponlinebackup/tmp was excluded.
17th Jun 2012 3.00.42 AM Information Database backup completed.
17th Jun 2012 3.00.37 AM Information Ignoring comments that are marked as spam.
17th Jun 2012 3.00.37 AM Information Ignoring comments in the trash.
17th Jun 2012 3.00.36 AM Information Synchronisation of backup data completed.
17th Jun 2012 3.00.30 AM Information Backup status is out of sync, synchronising with server...
17th Jun 2012 3.00.28 AM Information Initialisation completed.
17th Jun 2012 3.00.27 AM Information Backup starting...