An error happened at: disk.php(578)

Online Backup for WordPress Plugin Version 3.0.4
WordPress Version: 3.8.1 (standalone)
PHP Version: 5.2.17
Server Software: LiteSpeed
MySQL Server Version: 5.5.34-cll
MySQL Client Version: 1.0; MySQL Packet Size: 16 MiB
Memory: 256M; Post: 8M; Upload: 25M; Timeout: 30
Memory Changable: Yes; Admin Cache Size: 985.06 KiB
Status: 1 row, 21.72 KiB packet size, 928.73 KiB cache freed, 36.92 MiB memory used
Capabilities: gzdeflate php5hash DES AES128 AES192 AES256
End of Information

PROBLEM:
When I run a backup to Online Backup for WordPress Vault, it FAILS. However, when I choose Local – Generate a downoadable full backup… – SUCCESS.

I’ve tried these combinations of backups

1. VAULT Backup Database + Filesystem FAIL
2. LOCAL Backup Database + Filesystem SUCCEED

3. VAULT Backup Database only SUCCEED
4. VAULT Backup Filesystem only FAIL

When I performed backup 1. above, the error message is

The activity failed: An error happened at: disk.php(578) fopen(/home/suc19197/public_html/wp-content/plugins/wponlinebackup/tmp/backup.data.b202ad043a49523313f7a9eaa83198d658c40c41.php): failed to open stream: No such file or directory

Time Type Event
Time Type Event
31st Jan 2014 12.56.08 PM Error The activity failed: An error happened at: disk.php(578)
fopen(/home/suc19197/public_html/wp-content/plugins/wponlinebackup/tmp/backup.data.b202ad043a49523313f7a9eaa83198d658c40c41.php): failed to open stream: No such file or directory
31st Jan 2014 12.56.08 PM Information Deleted files processing completed.
31st Jan 2014 12.56.08 PM Information File collection completed.
31st Jan 2014 12.17.57 PM Information File system scan completed.
31st Jan 2014 12.15.28 PM Information Folder /public_html/wp-content/backups was excluded: Local backups directory
31st Jan 2014 12.15.23 PM Information Folder /public_html/wp-content/plugins/wponlinebackup/tmp was excluded: Temporary backup directory
31st Jan 2014 12.15.09 PM Information Database backup completed.
31st Jan 2014 12.15.02 PM Information Initialisation completed.
31st Jan 2014 12.15.02 PM Information Backup starting…

I have never had a successful vault backup of this filesystem, only to Local backup.

Can you help please

http://wordpress.org/plugins/wponlinebackup/