Yet still another way to get this symptom: I was rsync'ing from a remote machine over ssh to a Linux box with an NTFS-3G (FUSE) filesystem. Originally the filesystem was mounted at boot time and thus owned by root, and I was getting this error message when I did an rsync push from the remote machine. Then, as the user to which the rsync is pushed, I did:
$ sudo umount /shared
$ mount /shared
and the error messages went away.