CAUSE
This problem occurs when your users try to connect to a Web site whose address is something other than the root of the site. When the Windows XP WebDAV redirector issues an
OPTIONS request to verify WebDAV support on the site, the request is in the following format:
OPTIONS / HTTP/1.1
host: Web_site
Typically, this format is correct for root-level access of a WebDAV-enabled site. However, when the user tries to connect to an address under the root address, the
OPTIONS request must be in the following format:
OPTIONS /internal_path HTTP/1.1
host: Web_site
However, Windows XP does not use this format for WebDAV
OPTIONS requests.