svnadmin freeze error

Hey,

Trying to use the command shown here:
http://subversion.apache.org/docs/release-notes/1.8.html#svnadmin-freeze

command:

svnadmin freeze /svn/my-repos rsync -av /svn/my-repos /backup/my-repos

This is the error I get: "svnadmin: invalid option character: a"

I've verified that I'm using the latest version of subversion.

help?

-- 
Regards,
*Imad Sani*
Infrastructure Architect
116, Block DD (CCA)
Phase IV, D.H.A. Lahore
Tel: +92.42.37060558
*Bramerz.pk ** |  **Facebook.com/Bramerz.pk ** |  **Twitter.com/Bramerz*
*Save resources - Think before printing *
*Do not print this email unless necessary*
*DISCLAIMER*
This email including any attachment(s) contains information that is
privileged, private and confidential and is intended for the addressee(s)
only. If you receive this email in error, please notify the sender by reply
email and delete it from your system. Unauthorized use, disclosure,
distribution, printing, forwarding or copying is strictly prohibited. The
contents of this email do not necessarily represent the views or policies
of Bramerz (Pvt) Ltd. The email is scanned to be virus free however Bramerz
(Pvt) Ltd cannot accept responsibility for any loss or damage arising from
the use of this email or attachment(s).