XtraBackup Version string '' contains invalid data; ignoring

I’m not sure what’s happening here. The backups appear to be created, but innobackupex is throwing an error when I run:

/usr/bin/innobackupex-1.5.1 --compress=1 --user=“myuser” --password=“mypassword” --defaults-file="/etc/mysql/my.cnf" --stream=tar ./ | gzip - > /my-data-bak/xtrabackup/date +%Y-%m-%d_%H-%M-%S.tar.gz

Version string ‘’ contains invalid data; ignoring: ‘’ at /usr/bin/innobackupex-1.5.1 line 1636.
… lots of normal output, then:
101113 12:50:43 innobackupex-1.5.1: completed OK!

Anyone have any ideas what’s causing this? Is this an issue? The backups appear to restore fine.

Running Ubuntu Server 10.10, MySQL 5.5.6-rc, and xtrabackup_1.2-132.karmic.15_amd64.deb

(I’ve also added the Percona repositories as outlined in http://www.percona.com/docs/wiki/percona-server:release:star t - and it appears this is the latest release)

There is a fixed bug for MySQL Enterprise Backup for this issue and an open bug for XtraBackup.