After updating the panel, the backup still does not work.
If there is insufficient space in /usr/local/psa/PMM/tmp/ the copy remains in the server repository.
Expanding the space of /usr to a size larger than the copy, backup works correctly
regards
I have found that if the free space in / usr is smaller then the copy fails to copy to FTP. In my case is solved by expanding the space of / usr
We hope this update;)
Some more info here:
http://forum.parallels.com/showthread.php?288782-Backup-Problems-Plesk-11-5-40-MU3/page2
But I updated my sistem and no change.... :/