I am using Ubuntu 9.0.4 Jaunty and installed Rsync 3.0.6 protocol version 30
This is the problem i am facing while i connect through ssh which in turn use rsync for backup of the ubuntu machine on windows server were i have install cwrsync 3.0.1 (which also has rsync 3.0.6 protocol version 30) and also openSSH 4.1p1 version on windows and on ubuntu i have openSSH 5.1p1 version
Here is the problem :-
ssh: connect to host 192.168.1.198 port 22: Connection refused
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: unexplained error (code 255) at o.c(600) [sender=3.0.6]


And When i run the command on windows machine to take its backup on ubuntu machine then i got error as
Fatal error - c:\cwRsync\bin\ssh.exe: *** system shared memory version mismatch detected
This problem is probably due to using incompatible versions of the cygwin DLL.
rsync: read error: Connection reset by peer <104>
rsync error: error in rsync protocol data stream <code 12> at io.c<768> [sender=3.0.6]
Then i have download lastest version of cygwin.dll file kept at appropriate place,but still the same problem

Reinstall Cygwin?

For ssh, check the firewall and server cfg.