Lock request failed!! :s

 Hi everybody
My name is Malick and i have a problem with the subversion lock file system.
i got the following error when i tried to lock a file:
Erreur: Lock request failed: 405 Method Not Allowed (
http://mysvnserv<http://webserv/>
)
I installed Subversion 1.3.2 and i user TortoiseSVN as svn client.
In this page: http://svn.haxx.se/users/archive-2005-06/0559.shtml i read
that i must upgrade mod_dav_svn.
How can i do it?
Do i download this module?
There is a particular configuration on my apache2 configuration files?
Thank's a lot!!
I hope that I am well make understand, my english is so bad ;)
Best regards!!

-- 
El Hadji Malick GUEYE
Tel: +221 548 18 48
Site web: http://malick.site.voila.fr
BP: 13 147
Dakar/Senegal