I've been seeing this error too while transferring 1.5GB VM Images. Turning compression off fixes it.
According to this it is something to do with how rsync was compiled - whether it was using the internal or external zlib https://bugzilla.samba.org/show_bug.cgi?id=10372 -- Nick Craig-Wood <n...@craig-wood.com> -- http://www.craig-wood.com/nick -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org