DAV Authentication problem

I am trying to change the authentication from basic to digest because of a problem with Windows 7 64bit trying to authenticate. However, when I change from basic (doesn’t matter what I username mode I am using) I get this error -> Domian does not exist!

I am not sure what it is trying to tell me. DAV is enabled on the virtual server, the user is also DAV enabled and the /dav is showing as being the location path. I know DAV is working because I can get to the DAV directory through a browser login and through a DAV client. I just need to change the authentication to work with Win 7 64bit and I can’t seem to get it to change.

Does anyone have a suggestion???

Same issue here. Not sure what it might be. The WebDAV shares work but I am curious why I am unable to use the form.