error with innobackupex-1.5.1

my script is:
ssh -o “StrictHostKeyChecking no” host1 ‘innobackupex-1.5.1 --stream=tar --throttle=500 --socket=/data/var/mysql.sock --defaults-file=/root/my.cnf --user=root --password= --slave-info /data/ | nc 80’ < /dev/null > /data/xtrabackup.log 2>&1
the error is:
innobackupex-1.5.1: Created backup directory /data
innobackupex-1.5.1: Error: Failed to stream ‘backup-my.cnf’: Inappropriate ioctl for device at /usr/bin/innobackupex-1.5.1 line 542.

sometimes it is right,sometimes this meet this error.
thank you.

Please file a bug at Launchpad in the percona-xtrabackup project.

It looks like this is due to permission problems regarding the destination where innobackupex will write. It solved the problem for me at least running the script in sudo.