Webdav and wordpress

I installed wordpress and then set-up the themes directory as a webdav folder so I could upload new themes. But a strange thing happened. I access the webdav directory under macos 10.4 using the “connect to server” option under the “go” menu. If I try to upload a folder into the directory, the folder will copy, but then I get an error message telling me I can’t transfer the first file because it already exists in the directory. BUT, if I user a little webdav client (transmit) everything works fine. Any idea what’s going on here?