Webdav lock management

Hi everybody,

I'm looking for someone who could help me with the webdav protocol,
specially on web folder access.

I'm working on a web redirector project throught the webdav protocol.

I setup an iis 6.0 with webdav enabled, created a folder with right ACL, put
few documents in this folder and add a virtual directory in iis to map this
folder.

To summarize: My iis 6.0 server name with windows 2003 is frbtestsrv, my
ntfs folder => c:\inetpub\archives, my virtal folder in iis => archives to
acces a document through a client (windows XP pro SP1) i created a shortcut
in "My network place" => http://frbtestsrv/archives"

The user "toto" has a full access to the document "test.xls" stored in
http:\\frbtestsrv\archives, when toto open test.xls, the files is correctly
open in excel but strangely the original file is renamed in
test.xlsopequelocktoken:1e213213213 so nobody else can open this document
even in read only mode.

I thought that the webdav lock management was diffents, according to me when
a user open a file in read/write mode, antoher user should be able to open
the same file but in read only.

That seems not work correclty in my installation.

If someone has an idea ....

Any help would greatly appreciated.

Thanks in advance

Olivier