Configuring Lotus Domino WebDAV for third-party tools development has had us struggling a few days until we succeeded on make it actually work. There is a good article here that explains the basis of allowing WebDAV into your server.
However, that’s not all of it. The method above will never work unless you set the right permissions for the user ‘anonymous’ to the database you want to access. That’s it: individual database access must be configured, as it is explained here. The official reference can be also of help, although a bit outdated.
Even then, we had a lot of trouble working with the WebDAV enabled browsing. Under Windows 7 with Explorer, it seemed not allow any kind of file copying – but it allowed to create folders and files by right clicking directly on the directory, though. Also, we were having problems on MAC OS Finder in form of random write errors. All this stuff was pretty confusing and unclear on every forum and blog that we visited for help.