Getting all files and folders in SharePoint using WebDav

Getting all files and folders in SharePoint using WebDav

I try to get a list of files + folders from SharePoint using WebDav
according to the c# example here:
http://msdn.microsoft.com/en-us/library/ms992615(v=exchg.65).aspx
and I get error 501:
The server does not support the functionality that is required to fulfill
the request.
This is the appropriate response when the server does not recognize the
request method and is
not capable of supporting it for any resource. [HTTP/1.1]. Contrast with
Status Code 405.
So I understand it doesn't support the "SEARCH" keyword. I used other
stuff like delete, move, etc, and they worked fine.
Any idea what may cause the problem?
The problem occurs here:
// Send the SEARCH method request and get the
// response from the server.
Response = (HttpWebResponse)Request.GetResponse();