Running Plesk 10.4.4 with Centos 5.7

We are trying to run the plesk backup utility via terminal - However we are running into errors when it come to exporting via FTP.

Running the following works fine.
[root@server psa]# /usr/local/psa/bin/pleskbackup --domains-id 3
and
[root@server psa]# /usr/local/psa/bin/pleskbackup --domains-id 3 --output-file=/root/irregular-backups/domain1.tgz

However, when I try to export to FTP:

[root@server psa]# /usr/local/psa/bin/pleskbackup --domains-id 3 --output-file=ftp://00.00.000.000/array1/folder --ftp-login=**** --ftp-password=*****
Runtime error: The backup failed with errors!

Any ideas?