wdfs is a WebDAV that makes it possible to mount a WebDAV share under Linux, FreeBsd and apple mac OS X. wdfs has some special features for accessing subversion repositories via WebDAV. it's based on fuse and neon. WebDAV is an easy way to upload files through the services of a webserver.
Might be useful to get into the habit of using logs for later troubleshooting.
–size-only Modifies rsync’s “quick check” algorithm for finding files that need to be transferred, changing it from the default of transferring files with either a changed size or a changed last-modified time to just looking for files that have changed in size
Sounds like webdav clocks gets sufficiently out of sync with the local machine to cause trouble with rsync. I wonder if it leads to unnecessary download of entire files. Does this mean that unison won't work on webdav drives?